Code review comment for lp:~chiradeep/nova/msft-hyper-v-support

A couple of questions about the unittest provided with this branch:

- does the test require an actual connection to hyperv? I couldn't find where this is stubbed out
- any particular reasons of calling the private method _create_vm, rather the public spawn method?
- does this test actually run/pass at all?

The call to

  instance_ref = db.instance_create(None, instance)

should raise an exception about the deprecation of a null context