Move FakeQ2QService somewhere common.
Add a silly test for vertex.q2qclient.enregister.
Refactory vertex.q2qclient.enregister.
Make pyflakes happy.
Merge pull request #16 from twisted/q2qclient-tests

Update 'vertex register' to use newer idioms.

Reviewers: @cyli

This switches the register command to use an endpoint, rather than a `AMP` subclass with a `connectionMade`.