message: Default value for group_id should be null
diff: @@ -15,6 +15,13 @@ class NewChannelForm extends Component {
  static propTypes = {
  createChannel: PropTypes.func.isRequired,
  onClose: PropTypes.func.isRequired,
  + authorType: PropTypes.oneOf(['USER', 'GROUP']),
  + group_id: PropTypes.oneOfType([PropTypes.string, PropTypes.number]),
  + }
  +
  + static defaultProps = {
  + authorType: 'USER',
  + group_id: null,
  }
  state = {
  