UUID primary keys
Aha, scratch that I found the 1.0 -> 2.0 upgrade notes. My bad, closing...

For anyone finding this:

``` python
class MyModel(Model):
    uuid = UUIDField(primary_key=True)
    ...
```

I'd like to have `playhouse.postgres_ext.UUIDField` as the primary key for a table.

https://github.com/coleifer/peewee/issues/9 seems to suggest that this should be possible, but seems to have been deprecated since it's first introduction in 2012. Any suggestions?

Cheers,
Alex

PS. Awesome ORM, switched over from SQLAlchemy and loving every minute of it thus far!
