message: Corrected crumb and mount calculation
diff: @@ -69,9 +69,8 @@ class NavigationMotion extends React.Component<NavigationMotionProps, Navigation
  onRest={({key}) => this.clearScene(key)}
  duration={duration}>
  {styles => (
  - styles.map(({data: {key, state, data, crumbs}, style}) => {
  - var scene = !rootPerScene ? <Scene crumb={crumbs.length} />
  - : <SceneProxy crumb={crumbs.length} app={app} />;
  + styles.map(({data: {key, state, data}, style}) => {
  + var scene = !rootPerScene ? <Scene crumb={key} /> : <SceneProxy crumb={key} app={app} />;
  return children(style, scene, key, crumbs.length === key, state, data);
  }).concat(
  sharedElementMotion && sharedElementMotion({
  