Update dependency webpack-cli to v2.1.4

Author: renovate-bot

package.json

@@ -42,7 +42,7 @@
     "typescript": "2.8.1",
     "uglifyjs-webpack-plugin": "1.2.4",
     "webpack": "4.5.0",
-    "webpack-cli": "2.0.14",
+    "webpack-cli": "2.1.4",
     "webpack-serve": "0.3.1"
   },
   "directories": {