message: improve flow definitions
diff: @@ -24,11 +24,11 @@ type State = {
  class Rating extends Component<Props, State> {
  static defaultProps = {
  - className: null,
  + className: undefined,
  size: 'regular',
  rating: 0,
  maxRating: 5,
  - onRate: null,
  + onRate: undefined,
  disabled: false
  };
  