Fixed memory leak in DefaultAnimationsBuilder

[jferlisi]

When the animations get run there is a Handler that gets set on the Animation (Animation.mListenerHandler). This Handler holds a reference to the Activity. So caching the animations in a static field causes the Activity to be leaked. The fix was to remove the static fields that were caching the animation. Now the animations are created new each time.

[jferlisi]

Fixes #240

[Sloy]

Thank you @jferlisi for this. We're using your fix in the InfoJobs application. I had to fork your branch and made some changes to make it available via JitPack with compile 'com.github.Sloy:Crouton:465f251b5d'.

It removed our leak. So, thank you a lot! ❤️