Testing ROMS-Tools <-> C-Star integration in CI

[NoraLoose]

We should test the ROMS-Tools integration in the CI. And should ROMS-Tools be a (required or optional) dependency of C-Star as defined in pyproject.toml?

[TomNicholas]

In theory it's optional, at least in the same theoretical sense in which C-Star could support oceananigans.

[dafyddstephenson]

I think for alpha we should treat it as a dependency and make an issue to untangle them. My roms-tools integration PR will include a test (in the old format for now, sorry! I will take some time to study the pytest reformulation once it's in).