RCv3 positive integration tests

Closes #840.
As we are using an invalid lb_pool id to create the scaling group, shouldn't we be waiting for the servers to be deleted after otter attempts to add them to an invalid lb pool. Something like https://github.com/rackerlabs/otter/blob/master/autoscale_cloudroast/test_repo/autoscale/system/integration/test_system_integration_lbaas.py#L282