Tab bar translucent when hiding

Hi, first of all, thanks for this great library! I have noticed that when I add the tab bar as a follower it becomes translucent when animated. Why is that? Also, I noticed there is an arbitrary factor of 1.5 by which the delta is multiplicated. I think this assures that the bar hides entirely, but I have discovered that it's enough to multiply by 1.11 (at least for iPhone5 and iPhone6) - this is useful if you animate additional followers together with the tab bar.

I use:
`pod 'AMScrollingNavbar', '3.4.0'`

The code I'm asking about is lines 352-353 in the ScrollingNavigationController:

```
tabBar.isTranslucent = true
tabBar.frame.origin.y += delta * 1.5
```

Edit: Also, when I want to have a solid tab bar at all times, I need to remove all the offsets, like in line 26 of ScrollingNavbar+Sizes.swift. I have a feeling that I'm missing something here, is there a switch somewhere to allow solid tab bar?