message: export css from BaseCSS, allow children
diff: import preval from 'babel-plugin-preval/macro'
  -const baseCSS = preval`
  +const css = preval`
  const {join} = require('path')
  const sass = require('node-sass')
  const {css} = sass.renderSync({
  @@ -13,8 +13,9 @@ const baseCSS = preval`
  module.exports = css.toString()
  `
  -export default function BaseCSS(props) {
  - return <style>{baseCSS}</style>
  +export default function BaseCSS({children, ...rest}) {
  + // FIXME: {...rest} throws errors in styled-jsx ?
  + return <style>{css}{children}</style>
  }
  -export {baseCSS}
  +export {css}
  