ux(octicon): Fade octicon with transitions
ux(octicon): Fade octicon with transitions

Make for some extra smoothness in the UI.

jdetle/nteract,rgbkrk/nteract,captainsafia/nteract,temogen/nteract,jdfreder/nteract,captainsafia/nteract,jdfreder/nteract,nteract/composition,jdetle/nteract,rgbkrk/nteract,rgbkrk/nteract,jdfreder/nteract,nteract/nteract,rgbkrk/nteract,rgbkrk/nteract,jdetle/nteract,temogen/nteract,captainsafia/nteract,nteract/nteract,captainsafia/nteract,nteract/nteract,nteract/composition,temogen/nteract,nteract/nteract,nteract/nteract,nteract/composition,jdfreder/nteract,jdetle/nteract