Test multiple OpenFOAM versions (cron / on-demand)

[MakisH]

As we now support more and more OpenFOAM versions (see also precice/openfoam-adapter#128), it would be very helpful to have an automatic check that any changes in the OpenFOAM adapter (and only there), do not break compatibility with any of the supported OpenFOAM versions.

Needed OpenFOAM versions

In my view, we need to test the following versions only for building:

• Every supported version of the OpenFOAM Foundation, i.e. 4.1, 5.x, 6, 7, and dev
• The oldest supported OpenCFD version, i.e. v1706 (optional)
• The latest supported OpenCFD version, i.e. 2006 (expected any moment now)
• The develop branch of the OpenCFD version

Needed test cases

In terms of cases, it is enough to check the following cases with some otherwise non-checked version (e.g. latest Foundation):

• OpenFOAM-OpenFOAM flow-over-plate (CHT: Temperature + Heat Flux, buoyantPimpleFoam, laplacianFoam, implicit coupling)
• OpenFOAM-OpenFOAM flow-over-plate_nearest-projection (interpolation between face centers and face nodes)
• OpenFOAM-CalculiX heat_exchanger (CHT: Sink Temperature + Heat Transfer Coefficient)
• OpenFOAM-CalculiX flap_perp (FSI)
• Eventually (when merged), we should also add OpenFOAM-OpenFOAM pipe-pipe (Fluid-Fluid).

Implementation

It would be enough if this runs once per day/week and we definitely don't need automatic triggering from other repositories.

This could also be a nice way to start experimenting with the GitHub Actions for the system tests, as it could be independent and not interfere with the rest of the tests.

Technically, for all the Foundation versions there are Debian packages (for different Ubuntu versions per version) and for all the OpenCFD versions there are official Docker images.