chore(package): update webpackbar to version 4.0.0

Author: greenkeeper[bot]

package.json

@@ -52,7 +52,7 @@
     "uglifyjs-webpack-plugin": "^2.1.3",
     "vue-loader": "15.7.1",
     "vue-template-compiler": "^2.6.10",
-    "webpackbar": "^3.2.0"
+    "webpackbar": "^4.0.0"
   },
   "dependencies": {
     "animate.css": "^3.7.2",