adding push notification token to commandiq, fixes #233

@amillet89 @calvinfo for your review, adding tests and implementation just for the push notification token part of commandiq which wasn't really implemented before
one thing we're trying to do with facade is get rid of the `.proxy()` calls everywhere, since that usually signifies a problem with the spec that needs to be addressed. (though not always)

So if we can change this to be `.library().name` would be awesome.

Also @yields what do you think about updating facade to spec with the extra context methods