Update dependency tslint to v6

Author: renovate[bot]

package-lock.json

@@ -37,7 +37,7 @@
     "jest": "24.9.0",
     "rimraf": "3.0.2",
     "ts-jest": "24.3.0",
-    "tslint": "5.20.1",
+    "tslint": "6.1.3",
     "tslint-clean-code": "0.2.10",
     "tslint-microsoft-contrib": "6.2.0",
     "typescript": "3.9.10",