status dict

[drewgilliam]

Refactor status.json to contain a dictionary of stage status information. Update resumable tests given new status.json format.

Consider a pipeline containing the stages ["A", "B", "C"]. A status.json of the form

{
  "A": {"name", "A", "state", "done"},
  "B": {"name", "B", "state", "starting"},
}

indicates stage A is complete and stage B is starting.

A stage is injected with the status subdict for that stage. For example, the self object for stage B would contain

self.status == {"name": "B", "state": "starting"}