message: Spinner
  custom className supported
diff: @@ -17,7 +17,8 @@ export default class Spinner extends Component {
  size: PropTypes.number,
  androidStrokeWidth: PropTypes.number,
  on: PropTypes.bool,
  - progress: PropTypes.number
  + progress: PropTypes.number,
  + className: PropTypes.string
  };
  static defaultProps = {
  color: osname === ANDROID ? '#5181b8' : '#262626',
  @@ -28,7 +29,7 @@ export default class Spinner extends Component {
  progress: null
  };
  render () {
  - const { on, progress, size, style } = this.props;
  + const { on, progress, size, style, className } = this.props;
  const isAnimated = on && progress === null;
  const modifiers = {
  'Spinner--on': isAnimated
  @@ -37,7 +38,7 @@ export default class Spinner extends Component {
  const Component = osname === IOS ? IosSpinner : AndroidSpinner;
  return (
  - <div className={classnames(baseClassNames, modifiers)} style={style}>
  + <div className={classnames(baseClassNames, modifiers, className)} style={style}>
  <svg
  className="Spinner__self"
  style={{ width: size, height: size }}
  