Allow for running Alfalfa integration tests on non-local deployment

[TShapinsky]

Adds --host="<alflalfa_host>" option to pytest.

This allows for Alfalfa integration and API tests to be run on a remote instance. This is useful for validating a new deployment. After running these tests on on lab instances I discovered a small bug in the Alfalfa deployment helm chart which will be addressed in the next couple days.