bump(0.8.1)

Signed-off-by: Josh Kurz <jkurz25@gmail.com>
feat(v2): upgrade calendar to v2

Signed-off-by: Josh Kurz <josh.kurz@turner.com>
unHack(addEventSource): not checking for :isVisible when adding and removing event source

Signed-off-by: Josh Kurz <josh.kurz@turner.com>
Merge branch 'v2' of github.com:angular-ui/ui-calendar into v2