CSS Animations for transitions

Looking for some feedback on this.

Four different classes are applied not including the active class. (nextItemAnimationOut, nextItemAnimationIn, prevItemAnimationOut, prevItemAnimationIn).

For now it uses all the transitions found here: http://tympanus.net/Development/ItemTransitions/index2.html 
Any custom transition should work as long as it uses the classes set.

Tests are incoming.

Resolves #9