message: Used state on styleThatLeft instead of oldState
  The styleThatLeft on willLeave will always be populated because a
  leaving element always has style. This styleThatLeft will always have
  the state and data from its mounted style so no need to use oldState
  (and oldData)
diff: @@ -51,13 +51,13 @@ class NavigationMotion extends React.Component {
  return getStyle(style, state, data);
  }
  render() {
  - var {oldState, oldData, state, data, crumbs, nextCrumb} = this.getStateNavigator().stateContext;
  + var {state, data, crumbs, nextCrumb} = this.getStateNavigator().stateContext;
  var {unmountedStyle, style, children} = this.props;
  var sceneContexts = crumbs.concat(nextCrumb);
  return (state &&
  <TransitionMotion
  willEnter={() => getStyle(unmountedStyle, state, data, true)}
  - willLeave={({data: {state, data}}) => getStyle(unmountedStyle, state || oldState, data || oldData)}
  + willLeave={({data: {state, data}}) => getStyle(unmountedStyle, state, data)}
  styles={sceneContexts.map(({state, data, url}) => ({
  key: url,
  data: {scene: this.state.scenes[url], state, data},
  