ng-animation-detect - a new directive which tells you when animation starts, in-progress or ended

After doing some research, i found out that AngularJS was missing this very core feature. The current problem with CSS3 Animations is that you don't know when they ended. There should be a proper AngularJS directive which should inform you when it ended so you can proceed with your next functionality. 

For me, i needed to display a poll to user and animate it when he clicked on it. I had to wait for animation to finish to hide the poll with another animation. So there were series of CSS3 animation which should have been applied one after another. But there was no such directive therefore i had to write this on my own.