Adds `off` to UIView

since the tests pass as it currently is I thought it was fine - I'm about to head out for the evening but I'll give it a look later this weekend if I can slot some time.  Definitely want to update if its needed, but the tests imply that it's fine - maybe its because a bit down the stack there is a `flatten!` - [here](https://github.com/infinitered/rmq/blob/master/motion/ruby_motion_query/events.rb#L147)