message: add Text.propTypes
diff: import React from 'react'
  +import PropTypes from 'prop-types'
  import chameleon from './chameleon'
  import map, {classifier, valueMapper} from './props'
  @@ -22,4 +23,15 @@ const textProps = props => classifyTextProps(map(props))
  const Text = chameleon('span', textProps, true)
  +Text.propTypes = {
  + color: PropTypes.string,
  + fontSize: PropTypes.oneOfType([
  + PropTypes.number,
  + PropTypes.string
  + ]),
  + fontWeight: PropTypes.oneOf(['normal', 'bold', 'semibold']),
  + lineHeight: PropTypes.oneOf(['normal', 'condensed', 'condensed-ultra']),
  + mono: PropTypes.bool
  +}
  +
  export default Text
  