title: react navigation - how to change initial or root screen?
body: <p>I am using react native with react navigation for navigation. I added splash screen as inital screen : </p>
  
  <pre><code>const AppNavigator = createDrawerNavigator(
    {
      Splash: SplashScreen,
      Home: HomeScreen,
      Details: deScreen,
    },
    {
      initialRouteName: "Splash",
      contentComponent: SideMenuScreen
    }
  );
  </code></pre>
  
  <p>I am navigating to detail screen when i am click back using back button in android or calling following function to go back : </p>
  
  <pre><code>this.props.navigation.goBack();
  </code></pre>
  
  <p>goBack() close current screen and open initial screen i.e splash screen. </p>
  
  <p>How to change root or initial screen ? </p>