Use CI to run tests for batch systems

[kinow]

Describe exactly what you would like to see in an upcoming release

We have some new unit tests for batch schedulers, but no functional test that confirms it is working.

It would be nice to use the same CI infrastructure for running tests against PBS/Slurm/etc.

Additional context

See https://twitter.com/jiminy_crist/status/1174681602015813633?s=20 for an example.

Pull requests welcome!

[hjoliver]

(Re-opening - the issue that closed this was unit tests only).

[kinow]

Thanks. I was going to re-open or create a new issue but forgot. My intention with this issue was to actually have Slurm, PBS, etc. Whatever batch system we could use Docker to run on Travis CI or GitHub actions (both platforms support containers). Possibly include some scenarios with SSH too.