chore(deps): update dependency tslint to v5.20.0

Author: renovate-bot

package-lock.json

@@ -37,7 +37,7 @@
     "jest": "24.9.0",
     "rimraf": "3.0.0",
     "ts-jest": "24.0.2",
-    "tslint": "5.19.0",
+    "tslint": "5.20.0",
     "tslint-config-prettier": "1.18.0",
     "typescript": "3.6.2"
   },