chore(package): update webpack-cli to version 2.1.1

Author: greenkeeper[bot]

package.json

@@ -30,7 +30,7 @@
     "stylelint-scss": "3.1.0",
     "stylelint-webpack-plugin": "0.10.4",
     "webpack": "4.6.0",
-    "webpack-cli": "2.0.15"
+    "webpack-cli": "2.1.1"
   },
   "browserslist": [
     "> 0.5%",