change: upgrade pillow to 6.2.0 (#12)

GitHub notified us that there was an issue discovered in older versions of Pillow,
which could cause the library to either allocate very large amounts of memory or
take an extremely long period of time to process the image.

Author: laurenyu

setup.py

@@ -46,7 +46,7 @@ def read(fname):
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3.6',
     ],
-    install_requires=['numpy==1.16.4', 'Pillow==6.0.0', 'retrying==1.3.3', 'sagemaker-containers==2.5.4',
+    install_requires=['numpy==1.16.4', 'Pillow==6.2.0', 'retrying==1.3.3', 'sagemaker-containers==2.5.4',
                       'six==1.12.0', 'torch==1.2.0', 'requests_mock==1.6.0', 'sagemaker-inference==1.1.0',
                       'retrying==1.3.3'],
     extras_require={