message: get the asset prefix from __NEXT_DATA__
diff: @@ -5,34 +5,29 @@ import {parse} from 'url'
  // see: https://github.com/zeit/next-plugins/tree/master/packages/next-sass#usage
  import '../src/primer-react.scss'
  -const deployURL = process.env.NOW_URL || ''
  -const deployHostname = parse(deployURL).hostname
  -
  export default class MyDocument extends Document {
  - static getInitialProps({renderPage, req}) {
  + static getInitialProps({renderPage, req, ...rest}) {
  const sheet = new ServerStyleSheet()
  const page = renderPage(App => props => sheet.collectStyles(<App {...props} />))
  const styles = sheet.getStyleElement()
  - const {hostname} = req.headers
  - const baseURL = deployHostname && hostname !== deployHostname ? deployURL : ''
  - return {
  - ...page,
  - styles,
  - baseURL
  - }
  + return {...page, styles}
  }
  render() {
  - const {baseURL, styles} = this.props
  + const {
  + styles,
  + // this comes from the app.setAssetPrefix() call in server.js
  + __NEXT_DATA__: {assetPrefix = ''}
  + } = this.props
  return (
  <html lang="en">
  <Head>
  <title>primer-react</title>
  <meta charSet="utf8" />
  - <link rel="icon" href={`${baseURL}/assets/favicon.png`} />
  - <link rel="apple-touch-icon" href={`${baseURL}/assets/apple-touch-icon.png`} />
  - <link rel="stylesheet" href={`${baseURL}/_next/static/style.css`} />
  + <link rel="icon" href={`${assetPrefix}/static/assets/favicon.png`} />
  + <link rel="apple-touch-icon" href={`${assetPrefix}/static/assets/apple-touch-icon.png`} />
  + <link rel="stylesheet" href={`${assetPrefix}/_next/static/style.css`} />
  <meta name="viewport" content="width=device-width,initial-scale=1" />
  <meta name="generator" content="Compositor X0" />
  <meta name="og:title" content="Primer React" />
  