feat(package): update @easy-webpack/config-css to version 4.0.0 (#13)

BREAKING CHANGE: breaking update

Author: greenkeeperio-bot

package.json

@@ -46,7 +46,7 @@
     "typescript": "^2.0.6"
   },
   "dependencies": {
-    "@easy-webpack/config-css": "^3.0.0",
+    "@easy-webpack/config-css": "^4.0.0",
     "node-sass": "^3.10.1",
     "sass-loader": "^4.0.2"
   },