Add wrapping of where clause to adapter findQuery

Wrap the passed in query in a `{ where: }` if not already wrapped.  For brevity.

Been using this in my own project and seems to work pretty well, thought you guys may be interested in it.
Well, there are tests this behavior. The docs at https://parse.com/docs/rest#queries seem to confirm that where is supposed to be a JSON string. I can confirm the behavior, but also doubt this was incorrect.