chore(deps): update dependency tslint to v6

Author: renovate[bot]

example/package.json

@@ -20,6 +20,6 @@
     "typed-css-modules": "file:../"
   },
   "devDependencies": {
-    "tslint": "5.20.1"
+    "tslint": "6.1.3"
   }
 }