'@': resolve('src')
https://stackoverflow.com/questions/42749973/es6-import-using-at-sign-in-path-in-a-vue-js-project-using-webpack
https://github.com/vuejs-templates/webpack/blob/9992f5a058c53f32b03d9a8743612188c04698af/template/build/webpack.base.conf.js#L27