title: Disable going back in react-native using react-navigation
body: <p>I have been a lot of time searching and trying different stuff to disable going back once the "user" is logged in but it seams that NavigationActions does not work. This is the code:</p>
  
  <pre><code>import { NavigationActions } from 'react-navigation';
  
  const actionToDispatch = NavigationActions.reset({
      index: 0,
      actions: [NavigationActions.navigate('DrawerNavigator')] // Array!
    })
  
  export default class LoginScreen extends React.Component {
      constructor(props) {
          super(props);
        }
  
  
    render() {
  
      return (
          &lt;RkAvoidKeyboard
          style={styles.screen}
          onStartShouldSetResponder={ (e) =&gt; true}
          onResponderRelease={ (e) =&gt; Keyboard.dismiss()}&gt;
          &lt;View style={styles.content}&gt;
              &lt;Button title="Complete Login" onPress={()=&gt;this.props.navigation.dispatch(actionToDispatch)}/&gt;
            &lt;/View&gt;
        &lt;/RkAvoidKeyboard&gt;
      );
    }
  }
  </code></pre>
  
  <p>I shrinked a little bit the code. What happens is that the dispatch actions does not work. And also I get the error: undefined is not a function(evaluating '_reactNavigation.NavigationActions .......) so it does not even compile. I have the last version of React-navigation(2.12.0).</p>