更新的scss版本在vue cli3的项目里面的配置需要修改参数设置，具体在vue.config.js文件

sass-loader报错：
Module build failed (from ./node_modules/_sass-loader@8.0.0@sass-loader/dist/cjs.js):
ValidationError: Invalid options object. Sass Loader has been initialised using an options object that does not match the API
schema.

• options has an unknown property ‘data’. These properties are valid:
  object { implementation?, sassOptions?, prependData?, sourceMap?, webpackImporter? }
  at validate (D:\workspace\vuecli\elemdemo\node_modules_schema-utils@2.5.0@schema-utils\dist\validate.js:50:11)
  at Object.loader (D:\workspace\vuecli\elemdemo\node_modules_sass-loader@8.0.0@sass-loader\dist\index.js:36:28)
  解决方案：
  将 data 改成prependData

css: {
      loaderOptions: {
        sass: {
          prependData: `
            @import "@/assets/css/index.scss";
          `
        }
      }
    }