chore(deps): update dependency webpack-cli to v4

Author: renovate-bot

package.json

@@ -49,7 +49,7 @@
     "source-map-loader": "^1.0.1",
     "url-loader": "^4.1.0",
     "webpack": "^4.0.0",
-    "webpack-cli": "^3.3.11",
+    "webpack-cli": "^4.0.0",
     "webpack-dev-server": "^3.0.0",
     "webpack-node-externals": "^2.5.0"
   },