Unstub EditionsWorkflowControlllerTest

These tests were tightly coupled to the implementation, rendering them
useless once the implementation changed. I've unstubbed them as best
I can for now, turning them into mini-integration tests so we can be
sure that no behaviour has broken. Once we have service objects to
handle the complex logic for each workflow action, these tests will
be simplified down to basics, as the bulk of the logic will live
outside of the controller.