Update the overlord solution

Where did this come from? I'm guessing that it comes from the binding between clicking a button and waiting for Ajax. This is an example of Temporal Coupling, where two things happen near each other in time, so they're conflated. Instead, it'd be better to include a step that waits for Ajax to return explicitly and that is only called in `@javascript` scenarios. Switching to poltergeist for all tests would also work.