title: How to reset my stack in react-navigation?
body: <p>I have 5 tabs on my Home Screen. </p>
  
  <ul>
  <li>Home Tab</li>
  <li>Search tab</li>
  <li>AddPostTab</li>
  <li>Notifications Tab</li>
  <li>Profile Tab</li>
  </ul>
  
  <p>AddPostTab is like this. </p>
  
  <pre><code>const AddPostTab = createStackNavigator({
      AddPost: {
        screen: AddPost,
      },
      ImageDescription: {
        screen: ImageDescription
      },
      },
      {
        headerMode:'none',
        mode:'modal'
      }
  );
  </code></pre>
  
  <p>When I go back from <code>ImageDescription</code> screen to Home Screen and then if I go to <code>AddPostTab</code> again, I'm directly going to the <code>ImageDescription</code> screen. But I want to be able to go to AddPost screen.</p>
  
  <p>I've also tried </p>
  
  <pre><code> const resetAction = StackActions.reset({
                  index: 0,
                  actions: [
                      NavigationActions.navigate({ routeName: 'AddPost' }),
                  ],
                });
                this.props.navigation.dispatch(resetAction);
  </code></pre>
  
  <p>but this only takes me to the AddPost Screen. But if I use Home instead of AddPost, it doesn't works.
  How can I reset my stack in my case so that I can go to Home screen?</p>