title: React Native - ReactNavigation.addNavigationHelpers in not a function
body: <p>I was using react-navigation 1.2.1 and every thing was working fine as soon as I updated react-navigation to 2.0.0 it gives the following error. Any idea why it must be happening?</p>
  
  <blockquote>
    <p>ReactNavigation.addNavigationHelpers in not a function.</p>
  </blockquote>
  
  <pre><code>import * as ReactNavigation from 'react-navigation';
  
  render() {
      const { dispatch, nav } = this.props;
      const navigation = ReactNavigation.addNavigationHelpers({
        dispatch,
        state: nav,
        addListener,
      });
  
      return &lt;AppNavigation navigation={navigation} /&gt;;
    }
  
  //"react-navigation": "2.0.0",
  //"react-native": "0.53.3",
  //"redux": "^3.7.2"
  </code></pre>