Merge pull request #2497 from thelounge/renovate/webpack-cli-3.x

Update dependency webpack-cli to v3

package.json

@@ -101,7 +101,7 @@
     "textcomplete": "0.17.1",
     "undate": "0.3.0",
     "webpack": "4.10.2",
-    "webpack-cli": "2.1.5",
+    "webpack-cli": "3.0.1",
     "webpack-dev-server": "3.1.4"
   }
 }