webpack中添加px2rem-loader

在buid->util.js

  const px2remLoader = {
      loader: 'px2rem-loader',
      options: {
          remUnit: 75
      }
  }

// generate loader string to be used with extract text plugin
function generateLoaders (loader, loaderOptions) {
  const loaders = options.usePostCSS ? [cssLoader, postcssLoader,px2remLoader] : [cssLoader,px2remLoader]

  if (loader) {
    loaders.push({
      loader: loader + '-loader',
      options: Object.assign({}, loaderOptions, {
        sourceMap: options.sourceMap
      })
    })
  }

var px2remLoader = {

loader: 'px2rem-loader',

options: {

remUnit: 75

}

}