This is also a fantastic example of brittle code in action :D
If you find that updating with invalid credentials provides a 422 response, instead of the 200 response shown in the video, I think this is okay.
Check the projects_controller.rb, the 422 status is specified in the update action. I think its just an update to the jumpstart framework since the video was recorded. You should specify the error code in your test to match the controller specs as well, assert_response(422).
As Menno mentioned, the ControllerTest is now obsolete, rails is using IntegrationTest