[INSTALL]: pfunit 4.15.0

[mathomp4]

Package name

pfunit

Package version/tag

4.15.0

Build options

+mpi +fhamcrest

Installation timeframe

spack-stack-2.1.0

Other information

When we (GMAO) test GEOS/MAPL, we use pFUnit for unit tests. I realized it's not in spack-stack because it's not really needed for anything beyond that. But it'd be nice to have.

I did a test install at NAS and it looks like pfunit +mpi +fhamcrest has no new dependencies beyond what's already in spack-stack, so it should be simple.