A few API changes in djblets and kgb caused a couple breakages in the

rbintegrations tests. This change fixes those up.
In review, it was also pointed out that assertions inside callbacks that

come from something using SignalHook won't be recorded properly,

because the extension sandboxing swallows them. I've moved code around

so that we do all the assertions inside the test case code instead of in

deep callbacks.

Ran unit tests.