chore(deps): update dependency tslint-immutable to v4.9.1

Author: renovate-bot

package-lock.json

@@ -87,7 +87,7 @@
     "travis-cov": "0.2.5",
     "tslint": "5.11.0",
     "tslint-consistent-codestyle": "1.14.0",
-    "tslint-immutable": "4.9.0",
+    "tslint-immutable": "4.9.1",
     "typescript": "2.8.4"
   },
   "publishConfig": {