add early deprecation warning for <a-animation>
add early deprecation warning for <a-animation>

aframevr/aframe,aframevr/aframe,chenzlabs/aframe,mkungla/aframe,mkungla/aframe,chenzlabs/aframe,RSpace/aframe,dmarcos/aframe,ngokevin/aframe,RSpace/aframe,dmarcos/aframe,ngokevin/aframe