[codepen] css + append/prepend carousel

I recently learned that .appendChild() will automatically remove an element before inserting that element at the bottom of its parent if the element already existed.
I mean it's nothing really, even if it doesn't automatically do that we can just call .removeChild().
Anyway, here's some fun stuff with that! All transition and transformation are handled by css.
For much better quality, see it live here: http://codepen.io/d4rek/full/oxqXQa/