message: tidy, constrain bg and color props
diff: @@ -2,8 +2,9 @@ import React from 'react'
  import PropTypes from 'prop-types'
  import classnames from 'classnames'
  import Octicon from '@github/octicons-react'
  +import {colors} from './theme'
  -const CircleOcticon = ({size, bg, color, ...rest}) => {
  +export default function CircleOcticon({size, bg, color, ...rest}) {
  const className = classnames(
  'circle d-flex flex-items-center flex-justify-center',
  bg && `bg-${bg}`,
  @@ -22,12 +23,10 @@ CircleOcticon.defaultProps = {
  CircleOcticon.propTypes = {
  ...Octicon.propTypes,
  - bg: PropTypes.string,
  - color: PropTypes.string,
  + bg: PropTypes.oneOf(Object.keys(colors.bg)),
  + color: PropTypes.oneOf(Object.keys(colors)),
  // FIXME: we should be able to infer the size from the
  // rendered Octicon so that we can support
  // size={'small|medium|large'}
  size: PropTypes.number
  }
  -
  -export default CircleOcticon
  