chore: upgrade webpack-cli (#23)

Author: pierceray

package.json

@@ -33,7 +33,7 @@
     "react-dom": "^16.2.0",
     "style-loader": "^0.20.3",
     "webpack": "^4.17.1",
-    "webpack-cli": "^2.0.12"
+    "webpack-cli": "^3.1.2"
   },
   "scripts": {
     "test": "jest",