GitHub Action: Setup Fortran with Conda

[certik]

@jorgeg

MPI in a pain because of the MPI module needs to be compiled with the same compiler…in theory we could use vapaa, bind to that and that binds to C?

You can also use GitHub - lfortran/fortran_mpi, it works with GFortran and LFortran, we used it to compile the POT3D code. But it might not be as complete as Vapaa yet.