Update package.json

Author: superman66

package.json

@@ -7,7 +7,7 @@
   "private": false,
   "scripts": {
     "dev": "cross-env NODE_ENV=development webpack-dev-server --open --hot",
-    "build": "cross-env NODE_ENV=production webpack --progress --hide-modules"
+    "build": "rm -rf dist/ && cross-env NODE_ENV=production webpack --progress --hide-modules"
   },
   "dependencies": {
     "axios": "^0.15.3",