message: Created the twitter tab bar component layout
diff: import React from 'react';
  import {StateNavigator} from 'navigation';
  import {NavigationHandler} from 'navigation-react';
  -import {addNavigateHandlers, Scene} from 'navigation-react-native';
  +import {NavigationStack, TabBarIOS, TabBarItemIOS} from 'navigation-react-native';
  import Home from './Home';
  import Notifications from './Notifications';
  import Tweet from './Tweet';
  @@ -20,22 +20,27 @@ notifications.renderScene = () => <Notifications follows={getFollows()} />;
  tweet.renderScene = ({id}) => <Tweet tweet={getTweet(id)} />;
  timeline.renderScene = ({id}) => <Timeline timeline={getTimeline(id)} />;
  -for(var key in stateNavigator.states) {
  - var state = stateNavigator.states[key];
  - state.getCrumbStyle = from => from ? 'scale_in' : 'scale_out';
  - state.getUnmountStyle = from => from ? 'slide_in' : 'slide_out';
  -}
  -
  timeline.getTitle = ({sceneTitle}) => sceneTitle;
  -var stateNavigators = [stateNavigator, new StateNavigator(stateNavigator)];
  +var notificationsNavigator = new StateNavigator(stateNavigator);
  stateNavigator.navigate('home');
  -stateNavigators[1].navigate('notifications');
  -
  -addNavigateHandlers(stateNavigators);
  +notificationsNavigator.navigate('notifications');
  -export default ({crumb, tab = 0}) => (
  - <NavigationHandler stateNavigator={stateNavigators[tab]}>
  - <Scene crumb={crumb} tab={tab} />
  +export default () => (
  + <TabBarIOS>
  + <NavigationHandler stateNavigator={stateNavigator}>
  + <NavigationStack
  + crumbStyle={from => from ? 'scale_in' : 'scale_out'}
  + unmountStyle={from => from ? 'scale_in' : 'scale_out'}>
  + <TabBarItemIOS title="Home" />
  + </NavigationStack>
  + </NavigationHandler>
  + <NavigationHandler stateNavigator={notificationsNavigator}>
  + <NavigationStack
  + crumbStyle={from => from ? 'scale_in' : 'scale_out'}
  + unmountStyle={from => from ? 'scale_in' : 'scale_out'}>
  + <TabBarItemIOS title="Notifications" />
  + </NavigationStack>
  </NavigationHandler>
  + </TabBarIOS>
  );
  