Modern versions of kgb recommend passing an owner= parameter when

spying on unbound methods. This is to ensure compatibility with Python

3.x, which doesn't have a specific concept of an unbound method

(they're just standard functions). Not passing an explicit owner can

cause spies to conflict or to stay registered past the end of a test on

Python 3.x.
This change updates all our spies on unbound methods to specify an

explicit owner.

Unit tests pass.