Merge pull request #135 from abraham/renovate/webpack-cli-3.x

Update dependency webpack-cli to v3.0.4

package.json

@@ -66,6 +66,6 @@
     "uglifyjs-webpack-plugin": "1.2.5",
     "webpack": "4.12.0",
     "webpack-bundle-analyzer": "2.13.1",
-    "webpack-cli": "3.0.3"
+    "webpack-cli": "3.0.4"
   }
 }