Added 'onDrillDown' optional prop (#610)
Added 'onDrillDown' optional prop (#610)

* Added 'onDrillDown' optional prop

* Replaced else block with early return

jquense/react-big-calendar,TeaBough/react-big-calendar,jquense/react-big-calendar,intljusticemission/react-big-calendar,jquense/react-big-calendar