function configureDatepickerLocale (locale) {
  return Readable.from([`
const { registerLocale } = require('react-datepicker')
const locale = require('date-fns/locale/${locale}')
registerLocale('${locale}', locale)
  `])
}
'))
      .pipe(rev())
      .pipe(gulp.dest(dest))
      .pipe(rev.manifest(dest + '/rev-manifest.json', { base: dest, merge: true }))
      .pipe(gulp.dest(dest))
  }
}

function makeVendorTask (dest) {
  return function () {
    var b = browserify()
    return b
      .require('plotly.js-basic-dist')
      .require('zxcvbn')
      .plugin('tinyify', { noFlat: true })
      .bundle()
      .pipe(source('vendor.js'))
      .pipe(buffer())
      .pipe(gap.prependText('