Animating timer with Duration does not work unless on main thread

@andresinaka 
When animating the timer with duration, it doesnt work unless run on the mainthread like so...perhaps this should be done in the timer object otherwise you will be left wondering why it doesnt work.
```swift
DispatchQueue.main.async {
            snapTimer.animateOuterToValue(100, duration: 100, completion: nil)
        }