Changes to support the new RunConfig pattern in core

[jcrist]

Adds a new flow.run_config field that can be used instead of flow.environment to configure a flow run. There's likely more to do here, but so far this works with PrefectHQ/prefect#3333, see that PR for the full motivation.

[cicdw]

I realize this won't be fully ready until we merge the Core PR, but this looks straightforward to me! I left one comment on backwards compatibility

[jcrist]

I'm seeing errors about null run-config values, should that field be nullable (currently it's not, but afaict the server-side default should be being applied)?

[cicdw]

@jcrist the server_default is only used if you don't provide a value for run_config when inserting a new row. But our ORM will always provide a value (and in this case it's providing null). If you want to keep the non-nullability, you'll need to put a run_config or {} in the model before the insert.

[codecov-commenter]

Codecov Report

Merging #100 into master will increase coverage by 0.16%.
The diff coverage is 100.00%.

[jcrist]

I believe this is good to go.

[cicdw]

LGTM! Welcome to the server repo @jcrist :D