message: update Octicons API
diff: import React from 'react'
  import PropTypes from 'prop-types'
  -import Octicon from '@github/octicons-react'
  +import Octicon, {GitMerge} from '@github/octicons-react'
  import StateLabel from './StateLabel'
  const stateColorMap = {
  @@ -10,7 +10,9 @@ const stateColorMap = {
  pending: 'yellow'
  }
  -const MergeStatus = ({state}) => <StateLabel scheme={stateColorMap[state]} icon={<Octicon medium name="git-merge" />} />
  +const octicon = <Octicon icon={GitMerge} size="medium" />
  +
  +const MergeStatus = ({state}) => <StateLabel scheme={stateColorMap[state]} icon={octicon} />
  MergeStatus.propTypes = {
  state: PropTypes.oneOf(['ready', 'invalid', 'merged', 'pending']).isRequired
  