chore(deps): update dependency tslint to v6

Author: renovate[bot]

package-lock.json

@@ -33,7 +33,7 @@
     "prettier": "2.2.1",
     "commit-and-tag-version": "9.6.0",
     "ts-jest": "26.5.6",
-    "tslint": "5.20.1",
+    "tslint": "6.1.3",
     "typescript": "4.1.3"
   },
   "jest": {