Unexpected header behavior in TabNavigation

[EnriqueDev]

Version

Tell us which versions you are using:

• react-native-router-flux v4.0.0-beta.12
• react-native v0.47

Expected behaviour

When declaring a tab navigator I would like all the tabs to share the same header, so I guessed the proper way to do this would be:

<Scene key="ComponentLessScene" tabs swipeEnabled={true}>
    <Scene
         key="cs1"
         hideNavBar
         component={ComponentScene1} />
    <Scene
          key="cs2"
          hideNavBar
          component={ComponentScene2} />
</Scene> 

And so, the expected behaviour would be something like:

Actual behaviour

Instead what happens is this:

[aksonov]

You must add 'hideNavBar' for 'tabs' Scene to hide upper navbar.