Adding deprecation value to replace function

@cpennington @flowerhack @dianakhuang 
The replace function wasn't transmitting the deprecation property to the new object. This should fix that.

I'm 100% sure where I should put the unit test for this. Suggestions?
I don't think you need the `id` assertions in this test, since you're explicitly intending to test the status of the deprecated property, not of identity.