in our current configuration we have a workflow that:
1) builds the project
2) runs our unit tests
3) runs our dtests (distributed tests -- so we can test that particular C* features that can't be tested in a unit test)
ideally, there'd be another parameter instead of "requires" that allows the end user to control the execution order of a workflow but doesn't actually dictate that the "required" step ahead of it successfully completed
thinking a little more about this: maybe a new explicit keyword isn't required.... but instead circle should just respect the order in which the jobs were defined in the workflow.