message: get border colors from theme.js
diff: import React from 'react'
  import PropTypes from 'prop-types'
  import classnames from 'classnames'
  +import {colors} from './theme'
  import {mapWhitespaceProps, oneOrMoreOf, stylizer} from './props'
  -const borderColors = [
  - 'black-fade',
  - 'blue',
  - 'blue-light',
  - 'gray-dark',
  - 'gray-light',
  - 'green',
  - 'green-light',
  - 'purple',
  - 'red',
  - 'red-light',
  - 'yellow'
  -]
  +const borderColors = Object.keys(colors.border)
  const styleProps = ['width', 'minWidth', 'maxWidth', 'height', 'minHeight', 'maxHeight']
  -
  const stylize = stylizer(styleProps)
  function unique(values) {
  