diff --git a/.travis.yml b/.travis.yml
index 544e9295..fda62a81 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,10 +9,10 @@ android:
   components:
     - tools
     - tools
-    - android-25
+    - android-26
     - android-22
     - sys-img-armeabi-v7a-android-22
-    - build-tools-25.0.2
+    - build-tools-26.0.2
     - platform-tools
     - extra-android-support
     - extra-android-m2repository
diff --git a/SampleApp/build.gradle b/SampleApp/build.gradle
index 01d4c570..ba4f95fb 100644
--- a/SampleApp/build.gradle
+++ b/SampleApp/build.gradle
@@ -3,7 +3,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.0'
+        classpath 'com.android.tools.build:gradle:3.0.0'
     }
 }
 
@@ -17,13 +17,13 @@ repositories {
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.2"
+    compileSdkVersion 26
+    buildToolsVersion "26.0.2"
 
     defaultConfig {
         applicationId "io.card.development"
         minSdkVersion 18
-        targetSdkVersion 25
+        targetSdkVersion 26
         versionCode 1
         versionName "1.0.0"
         testInstrumentationRunner 'android.support.test.runner.AndroidJUnitRunner'
diff --git a/SampleApp/src/main/java/io/card/development/SampleActivity.java b/SampleApp/src/main/java/io/card/development/SampleActivity.java
index ac3a5120..0e457985 100644
--- a/SampleApp/src/main/java/io/card/development/SampleActivity.java
+++ b/SampleApp/src/main/java/io/card/development/SampleActivity.java
@@ -30,7 +30,6 @@
 import io.card.payment.i18n.locales.LocalizedStringsList;
 
 public class SampleActivity extends Activity {
-
     protected static final String TAG = SampleActivity.class.getSimpleName();
 
     private static final int REQUEST_SCAN = 100;
@@ -56,6 +55,7 @@ public class SampleActivity extends Activity {
     private CheckBox mUseCardIOLogoToggle;
     private CheckBox mShowPayPalActionBarIconToggle;
     private CheckBox mKeepApplicationThemeToggle;
+    private CheckBox mHideTorchButtonToggle;
     private Spinner mLanguageSpinner;
     private EditText mUnblurEdit;
 
@@ -64,32 +64,29 @@ public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.sample_activity);
 
-        mManualToggle = (CheckBox) findViewById(R.id.force_manual);
-        mEnableExpiryToggle = (CheckBox) findViewById(R.id.gather_expiry);
-        mScanExpiryToggle = (CheckBox) findViewById(R.id.scan_expiry);
-        mCvvToggle = (CheckBox) findViewById(R.id.gather_cvv);
-        mPostalCodeToggle = (CheckBox) findViewById(R.id.gather_postal_code);
-        mPostalCodeNumericOnlyToggle = (CheckBox) findViewById(R.id.postal_code_numeric_only);
-        mCardholderNameToggle = (CheckBox) findViewById(R.id.gather_cardholder_name);
-        mSuppressManualToggle = (CheckBox) findViewById(R.id.suppress_manual);
-        mSuppressConfirmationToggle = (CheckBox) findViewById(R.id.suppress_confirmation);
-        mSuppressScanToggle = (CheckBox) findViewById(R.id.detect_only);
-
-        mUseCardIOLogoToggle = (CheckBox) findViewById(R.id.use_card_io_logo);
-        mShowPayPalActionBarIconToggle = (CheckBox) findViewById(R.id.show_paypal_action_bar_icon);
-        mKeepApplicationThemeToggle = (CheckBox) findViewById(R.id.keep_application_theme);
-
-        mLanguageSpinner = (Spinner) findViewById(R.id.language);
-        mUnblurEdit = (EditText) findViewById(R.id.unblur);
-
-        mResultLabel = (TextView) findViewById(R.id.result);
-        mResultImage = (ImageView) findViewById(R.id.result_image);
-        mResultCardTypeImage = (ImageView) findViewById(R.id.result_card_type_image);
-
-        TextView version = (TextView) findViewById(R.id.version);
+        mManualToggle = findViewById(R.id.force_manual);
+        mEnableExpiryToggle = findViewById(R.id.gather_expiry);
+        mScanExpiryToggle = findViewById(R.id.scan_expiry);
+        mCvvToggle = findViewById(R.id.gather_cvv);
+        mPostalCodeToggle = findViewById(R.id.gather_postal_code);
+        mPostalCodeNumericOnlyToggle = findViewById(R.id.postal_code_numeric_only);
+        mCardholderNameToggle = findViewById(R.id.gather_cardholder_name);
+        mSuppressManualToggle = findViewById(R.id.suppress_manual);
+        mSuppressConfirmationToggle = findViewById(R.id.suppress_confirmation);
+        mSuppressScanToggle = findViewById(R.id.detect_only);
+        mUseCardIOLogoToggle = findViewById(R.id.use_card_io_logo);
+        mShowPayPalActionBarIconToggle = findViewById(R.id.show_paypal_action_bar_icon);
+        mKeepApplicationThemeToggle = findViewById(R.id.keep_application_theme);
+        mHideTorchButtonToggle = findViewById(R.id.hide_torch_button);
+        mLanguageSpinner = findViewById(R.id.language);
+        mUnblurEdit = findViewById(R.id.unblur);
+        mResultLabel = findViewById(R.id.result);
+        mResultImage = findViewById(R.id.result_image);
+        mResultCardTypeImage = findViewById(R.id.result_card_type_image);
+
+        TextView version = findViewById(R.id.version);
         version.setText("card.io library: " + CardIOActivity.sdkVersion() + "\n" +
                 "Build date: " + CardIOActivity.sdkBuildDate());
-
         setScanExpiryEnabled();
         setupLanguageList();
     }
@@ -116,39 +113,35 @@ public void onScan(View pressed) {
                 .putExtra(CardIOActivity.EXTRA_LANGUAGE_OR_LOCALE, (String) mLanguageSpinner.getSelectedItem())
                 .putExtra(CardIOActivity.EXTRA_USE_PAYPAL_ACTIONBAR_ICON, mShowPayPalActionBarIconToggle.isChecked())
                 .putExtra(CardIOActivity.EXTRA_KEEP_APPLICATION_THEME, mKeepApplicationThemeToggle.isChecked())
+                .putExtra(CardIOActivity.EXTRA_HIDE_TORCH_BUTTON, mHideTorchButtonToggle.isChecked())
                 .putExtra(CardIOActivity.EXTRA_GUIDE_COLOR, Color.GREEN)
                 .putExtra(CardIOActivity.EXTRA_SUPPRESS_CONFIRMATION, mSuppressConfirmationToggle.isChecked())
                 .putExtra(CardIOActivity.EXTRA_SUPPRESS_SCAN, mSuppressScanToggle.isChecked())
                 .putExtra(CardIOActivity.EXTRA_RETURN_CARD_IMAGE, true);
-
         try {
             int unblurDigits = Integer.parseInt(mUnblurEdit.getText().toString());
             intent.putExtra(CardIOActivity.EXTRA_UNBLUR_DIGITS, unblurDigits);
-        } catch(NumberFormatException ignored) {}
-
+        } catch (NumberFormatException ignored) {
+        }
         startActivityForResult(intent, REQUEST_SCAN);
     }
 
     public void onAutotest(View v) {
         Log.i(TAG, "\n\n\n ============================== \n" + "successfully completed "
                 + numAutotestsPassed + " tests\n" + "beginning new test run\n");
-
         Intent intent = new Intent(this, CardIOActivity.class)
                 .putExtra(CardIOActivity.EXTRA_REQUIRE_EXPIRY, false)
                 .putExtra(CardIOActivity.EXTRA_REQUIRE_CVV, false)
                 .putExtra(CardIOActivity.EXTRA_REQUIRE_POSTAL_CODE, false)
                 .putExtra(CardIOActivity.EXTRA_REQUIRE_CARDHOLDER_NAME, false)
                 .putExtra("debug_autoAcceptResult", true);
-
         startActivityForResult(intent, REQUEST_AUTOTEST);
-
         autotestMode = true;
     }
 
     @Override
     public void onStop() {
         super.onStop();
-
         mResultLabel.setText("");
     }
 
@@ -157,7 +150,7 @@ protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         super.onActivityResult(requestCode, resultCode, data);
         Log.v(TAG, "onActivityResult(" + requestCode + ", " + resultCode + ", " + data + ")");
 
-        String outStr = new String();
+        String outStr = "";
         Bitmap cardTypeImage = null;
 
         if ((requestCode == REQUEST_SCAN || requestCode == REQUEST_AUTOTEST) && data != null
@@ -204,9 +197,7 @@ public void run() {
         Bitmap card = CardIOActivity.getCapturedCardImage(data);
         mResultImage.setImageBitmap(card);
         mResultCardTypeImage.setImageBitmap(cardTypeImage);
-
         Log.i(TAG, "Set result: " + outStr);
-
         mResultLabel.setText(outStr);
     }
 
diff --git a/SampleApp/src/main/res/layout/sample_activity.xml b/SampleApp/src/main/res/layout/sample_activity.xml
index 5444e783..7d93713b 100644
--- a/SampleApp/src/main/res/layout/sample_activity.xml
+++ b/SampleApp/src/main/res/layout/sample_activity.xml
@@ -15,7 +15,7 @@
             android:id="@+id/version"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:paddingBottom="8dp"/>
+            android:paddingBottom="8dp" />
 
         <LinearLayout
             android:layout_width="match_parent"
@@ -28,8 +28,8 @@
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
                 android:checked="false"
-                android:text="Expiry"
-                android:onClick="onExpiryToggle"/>
+                android:onClick="onExpiryToggle"
+                android:text="Expiry" />
 
             <CheckBox
                 android:id="@+id/gather_cvv"
@@ -37,7 +37,7 @@
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
                 android:checked="false"
-                android:text="CVV"/>
+                android:text="CVV" />
 
             <CheckBox
                 android:id="@+id/gather_postal_code"
@@ -45,7 +45,7 @@
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
                 android:checked="false"
-                android:text="Postal Code"/>
+                android:text="Postal Code" />
 
         </LinearLayout>
 
@@ -53,95 +53,101 @@
             android:id="@+id/gather_cardholder_name"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="Cardholder Name"/>
+            android:text="Cardholder Name" />
 
         <CheckBox
             android:id="@+id/postal_code_numeric_only"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="Restrict Postal Code to Numeric Only"/>
+            android:text="Restrict Postal Code to Numeric Only" />
 
         <CheckBox
             android:id="@+id/scan_expiry"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="Scan Expiry"
-            android:checked="true"/>
+            android:checked="true"
+            android:text="Scan Expiry" />
 
         <CheckBox
             android:id="@+id/force_manual"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="Force keyboard entry (bypass scan)"/>
+            android:text="Force keyboard entry (bypass scan)" />
 
         <CheckBox
             android:id="@+id/suppress_manual"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="Suppress keyboard number entry"/>
+            android:text="Suppress keyboard number entry" />
 
         <CheckBox
             android:id="@+id/suppress_confirmation"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="Suppress confirmation"/>
+            android:text="Suppress confirmation" />
 
         <CheckBox
             android:id="@+id/detect_only"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="Detect card-ish rectangle only"/>
+            android:text="Detect card-ish rectangle only" />
 
         <CheckBox
             android:id="@+id/use_card_io_logo"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="Use card.io logo"/>
+            android:text="Use card.io logo" />
 
         <CheckBox
             android:id="@+id/show_paypal_action_bar_icon"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="PayPal icon in action bar"/>
+            android:text="PayPal icon in action bar" />
 
         <CheckBox
             android:id="@+id/keep_application_theme"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:text="Keep application theme"/>
+            android:text="Keep application theme" />
+
+        <CheckBox
+            android:id="@+id/hide_torch_button"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="Hide torch button" />
 
         <LinearLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:orientation="horizontal"
-            android:focusableInTouchMode="true">
+            android:focusableInTouchMode="true"
+            android:orientation="horizontal">
 
             <TextView
                 android:layout_width="wrap_content"
                 android:layout_height="match_parent"
                 android:gravity="center"
-                android:text="Language:"/>
+                android:text="Language:" />
 
             <Spinner
                 android:id="@+id/language"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
-                android:gravity="center"/>
+                android:gravity="center" />
 
             <TextView
                 android:layout_width="wrap_content"
                 android:layout_height="match_parent"
                 android:gravity="center"
                 android:paddingLeft="50dp"
-                android:text="Digits not blurred:"/>
+                android:text="Digits not blurred:" />
 
             <EditText
                 android:id="@+id/unblur"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:text="4"
                 android:gravity="center"
-                android:inputType="number"/>
+                android:inputType="number"
+                android:text="4" />
 
         </LinearLayout>
 
@@ -155,8 +161,8 @@
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:layout_weight="0.4"
-                android:text="Scan Credit Card using Card.io"
-                android:onClick="onScan"/>
+                android:onClick="onScan"
+                android:text="Scan Credit Card using Card.io" />
 
             <Button
                 android:id="@+id/auto_test"
@@ -164,7 +170,7 @@
                 android:layout_height="wrap_content"
                 android:layout_weight="0.3"
                 android:onClick="onAutotest"
-                android:text="Auto-test loop"/>
+                android:text="Auto-test loop" />
 
         </LinearLayout>
 
@@ -172,22 +178,22 @@
             android:id="@+id/recordings"
             android:layout_width="match_parent"
             android:layout_height="50dp"
-            android:visibility="gone"/>
+            android:visibility="gone" />
 
         <TextView
             android:id="@+id/result"
             android:layout_width="match_parent"
-            android:layout_height="wrap_content"/>
+            android:layout_height="wrap_content" />
 
         <ImageView
             android:id="@+id/result_card_type_image"
             android:layout_width="match_parent"
-            android:layout_height="wrap_content"/>
+            android:layout_height="wrap_content" />
 
         <ImageView
             android:id="@+id/result_image"
             android:layout_width="match_parent"
-            android:layout_height="wrap_content"/>
+            android:layout_height="wrap_content" />
 
     </LinearLayout>
 
diff --git a/build.gradle b/build.gradle
index 415f8368..490a8edd 100644
--- a/build.gradle
+++ b/build.gradle
@@ -3,7 +3,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.0'
+        classpath 'com.android.tools.build:gradle:3.0.0'
         classpath "io.codearte.gradle.nexus:gradle-nexus-staging-plugin:0.5.3"
     }
 }
@@ -11,6 +11,6 @@ buildscript {
 task assemble {}
 
 ext {
-    sdkVersion = 25
-    buildToolsVersion = '25.0.2'
+    sdkVersion = 26
+    buildToolsVersion = '26.0.2'
 }
diff --git a/card.io/src/main/java/io/card/payment/CardIOActivity.java b/card.io/src/main/java/io/card/payment/CardIOActivity.java
index 961eb522..41f897cf 100644
--- a/card.io/src/main/java/io/card/payment/CardIOActivity.java
+++ b/card.io/src/main/java/io/card/payment/CardIOActivity.java
@@ -175,6 +175,12 @@ public final class CardIOActivity extends Activity {
      */
     public static final String EXTRA_HIDE_CARDIO_LOGO = "io.card.payment.hideLogo";
 
+    /**
+     * Boolean extra. Optional. Defaults to <code>false</code>. When set to <code>true</code> the
+     * flash camera toggle button will not be shown overlaid on the camera.
+     */
+    public static final String EXTRA_HIDE_TORCH_BUTTON = "io.card.payment.hideCameraFlashButton";
+
     /**
      * String extra. Optional. Used to display instructions to the user while they are scanning
      * their card.
@@ -275,7 +281,7 @@ public final class CardIOActivity extends Activity {
 
     private static final float UIBAR_VERTICAL_MARGIN_DP = 15.0f;
 
-    private static final long[] VIBRATE_PATTERN = { 0, 70, 10, 40 };
+    private static final long[] VIBRATE_PATTERN = {0, 70, 10, 40};
 
     private static final int TOAST_OFFSET_Y = -75;
 
@@ -290,19 +296,18 @@ public final class CardIOActivity extends Activity {
 
     private CreditCard mDetectedCard;
     private Rect mGuideFrame;
+    private LinearLayout customOverlayLayout;
+    private RelativeLayout mUIBar;
+    private FrameLayout mMainLayout;
+    private CardScanner mCardScanner;
+
     private int mLastDegrees;
     private int mFrameOrientation;
     private boolean suppressManualEntry;
     private boolean mDetectOnly;
-    private LinearLayout customOverlayLayout;
+    private boolean mHideTorchButton;
     private boolean waitingForPermission;
-
-    private RelativeLayout mUIBar;
-    private FrameLayout mMainLayout;
     private boolean useApplicationTheme;
-
-    private CardScanner mCardScanner;
-
     private boolean manualEntryFallbackOrForced = false;
 
     /**
@@ -337,6 +342,8 @@ protected void onCreate(Bundle savedInstanceState) {
         ResolveInfo resolveInfo;
         String errorMsg;
 
+        mHideTorchButton = clientData.getBooleanExtra(EXTRA_HIDE_TORCH_BUTTON, false);
+
         // Check for DataEntryActivity's portrait orientation
 
         // Check for CardIOActivity's orientation config in manifest
@@ -357,7 +364,7 @@ protected void onCreate(Bundle savedInstanceState) {
 
         if (clientData.getBooleanExtra(EXTRA_NO_CAMERA, false)) {
             manualEntryFallbackOrForced = true;
-        } else if (!CardScanner.processorSupported()){
+        } else if (!CardScanner.processorSupported()) {
             manualEntryFallbackOrForced = true;
         } else {
             try {
@@ -381,7 +388,27 @@ protected void onCreate(Bundle savedInstanceState) {
                 handleGeneralExceptionError(e);
             }
         }
+    }
+
+    @Override
+    protected void onRestoreInstanceState(Bundle savedInstanceState) {
+        super.onRestoreInstanceState(savedInstanceState);
+//        suppressManualEntry = savedInstanceState.getBoolean(EXTRA_SUPPRESS_MANUAL_ENTRY);
+//        mDetectOnly = savedInstanceState.getBoolean(EXTRA_SUPPRESS_SCAN);
+//        mHideTorchButton = savedInstanceState.getBoolean(EXTRA_HIDE_TORCH_BUTTON);
+//        useApplicationTheme = savedInstanceState.getBoolean(EXTRA_KEEP_APPLICATION_THEME);
+//        manualEntryFallbackOrForced = savedInstanceState.getBoolean(EXTRA_MANUAL_ENTRY_RESULT);
+    }
 
+    @Override
+    protected void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        outState.putBoolean(BUNDLE_WAITING_FOR_PERMISSION, waitingForPermission);
+//        outState.putBoolean(EXTRA_SUPPRESS_MANUAL_ENTRY, suppressManualEntry);
+//        outState.putBoolean(EXTRA_SUPPRESS_SCAN, mDetectOnly);
+//        outState.putBoolean(EXTRA_HIDE_TORCH_BUTTON, mHideTorchButton);
+//        outState.putBoolean(EXTRA_KEEP_APPLICATION_THEME, useApplicationTheme);
+//        outState.putBoolean(EXTRA_MANUAL_ENTRY_RESULT, manualEntryFallbackOrForced);
     }
 
     private void android23AndAboveHandleCamera() {
@@ -393,7 +420,6 @@ private void android23AndAboveHandleCamera() {
         }
     }
 
-
     private void android22AndBelowHandleCamera() {
         if (manualEntryFallbackOrForced) {
             finishIfSuppressManualEntry();
@@ -459,8 +485,8 @@ private void showCameraScannerOverlay() {
                 Class<?> testScannerClass = Class.forName("io.card.payment.CardScannerTester");
                 Constructor<?> cons = testScannerClass.getConstructor(this.getClass(),
                         Integer.TYPE);
-                mCardScanner = (CardScanner) cons.newInstance(new Object[] { this,
-                        mFrameOrientation });
+                mCardScanner = (CardScanner) cons.newInstance(new Object[]{this,
+                        mFrameOrientation});
             } else {
                 mCardScanner = new CardScanner(this, mFrameOrientation);
             }
@@ -575,13 +601,6 @@ protected void onResume() {
         }
     }
 
-    @Override
-    protected void onSaveInstanceState(Bundle outState) {
-        super.onSaveInstanceState(outState);
-
-        outState.putBoolean(BUNDLE_WAITING_FOR_PERMISSION, waitingForPermission);
-    }
-
     @Override
     protected void onPause() {
         super.onPause();
@@ -759,9 +778,9 @@ void onCardDetected(Bitmap detectedBitmap, DetectionInfo dInfo) {
         float sf;
         if (mFrameOrientation == ORIENTATION_PORTRAIT
                 || mFrameOrientation == ORIENTATION_PORTRAIT_UPSIDE_DOWN) {
-            sf = mGuideFrame.right / (float)CardScanner.CREDIT_CARD_TARGET_WIDTH * .95f;
+            sf = mGuideFrame.right / (float) CardScanner.CREDIT_CARD_TARGET_WIDTH * .95f;
         } else {
-            sf = mGuideFrame.right / (float)CardScanner.CREDIT_CARD_TARGET_WIDTH * 1.15f;
+            sf = mGuideFrame.right / (float) CardScanner.CREDIT_CARD_TARGET_WIDTH * 1.15f;
         }
 
         Matrix m = new Matrix();
@@ -908,7 +927,8 @@ private void setPreviewLayout() {
                 LayoutParams.MATCH_PARENT, Gravity.TOP));
         previewFrame.addView(mPreview);
 
-        mOverlay = new OverlayView(this, null, Util.deviceSupportsTorch(this));
+        boolean showTorch = Util.deviceSupportsTorch(this) && !mHideTorchButton;
+        mOverlay = new OverlayView(this, null, showTorch);
         mOverlay.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,
                 LayoutParams.MATCH_PARENT));
         if (getIntent() != null) {
@@ -968,7 +988,7 @@ public void onClick(View v) {
             });
             mUIBar.addView(keyboardBtn);
             ViewUtil.styleAsButton(keyboardBtn, false, this, useApplicationTheme);
-            if(!useApplicationTheme){
+            if (!useApplicationTheme) {
                 keyboardBtn.setTextSize(Appearance.TEXT_SIZE_SMALL_BUTTON);
             }
             keyboardBtn.setMinimumHeight(ViewUtil.typedDimensionValueToPixelsInt(
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 0a48d7d6..d09d2ec7 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip