Update dependency tslint to v6

Author: renovate-bot

package.json

@@ -47,7 +47,7 @@
     "karma-jasmine-html-reporter": "1.5.4",
     "protractor": "7.0.0",
     "ts-node": "8.10.1",
-    "tslint": "5.20.1",
+    "tslint": "6.1.3",
     "typescript": "3.8.3"
   }
 }