首先安装相关依赖：
npm install node-sass --save-dev
npm install sass-loader --save-dev
cnpm install style-loader --save-dev
npm install sass-resources-loader --save-dev build文件夹下util.js更改scss的值：
scss: generateLoaders('sass').concat({
loader: 'sass-resources-loader',
options:{
resources: path.resolve(__dirname,'../src/assets/scss/index.scss')
}
}),
