BUG SlideMenu + TabBar, TabItem are not visible

Hi,

First thanks for your POD, awesome work
I found an issue when I try to add the SlideMenu in a TabBar.

You can test it with the following code (your code updated) :

let mainViewController = storyboard.instantiateViewController(withIdentifier: "MainViewController") as! MainViewController
let leftViewController = storyboard.instantiateViewController(withIdentifier: "LeftViewController") as! LeftViewController

let rightViewController = storyboard.instantiateViewController(withIdentifier: "RightViewController") as! RightViewController

let slideMenuController = SlideMenuController(mainViewController: mainViewController, leftMenuViewController: leftViewController)

let tabBarController = UITabBarController()
tabBarController.viewControllers = [slideMenuController]
self.window?.rootViewController = tabBarController
self.window?.makeKeyAndVisible()`

You would see the TabBar like this :

In normal case, if you add a simple view controller, for example in previous code :

`tabBarController.viewControllers = [mainViewController]`

You would see the TabBar like this :

This "gray subview" hide TabBarItem, any idea ?

Thanks

Start with the provided SlideMenuController and UITabBarController reproduction, comparing it with the direct mainViewController case. Inspect how the SlideMenuController is embedded and how its gray subview is laid out relative to the tab bar. Done means the TabBarItem remains visible when SlideMenuController is used as a tab bar controller child.

Written by the indexing model from the issue text.