refine npm script

package.json

@@ -8,7 +8,7 @@
     "dev": "webpack-dev-server --inline --progress --config build/webpack.dev.conf.js",
     "start": "npm run dev",
     "build": "node build/build.js",
-    "build:report": "npm_config_report=true node build/build.js",
+    "build:report": "npm_config_report=true npm run build",
     "lint": "eslint --ext .js,.vue src",
     "test": "npm run lint"
   },