add animations and keyframes mixins from 'http://zerosixthree.se/8-sass-mixins-you-must-have-in-your-toolbox/'

Change-Id: I23beda6d143ffa5a14d411007abce9914448e343
add animations and keyframes mixins from http://zerosixthree.se/8-sass-mixins-you-must-have-in-your-toolbox/

Change-Id: Ifb32d23a24a1476c9332a64bddb2312a8af675ee
merge

Change-Id: Id0d944be11ac08847fa372bbf4e5cd82f0bcd162