Feature: Asynchronous CLI

[timothepearce]

Asynchronous CLI to develop:

synda generate config.yaml     # create and start
synda create config.yaml         # store a run in db
synda start run_id                     # start a run
synda pause run_id                  # pause a run
synda stop run_id                     # stop a run
synda resume run_id                # only for "paused" run
synda retry run_id                    # only for "failed" run

[timothepearce]

We could use https://github.com/PrefectHQ/prefect