Fix for ExtData2G unit test on discover GNU

[mathomp4]

Types of change(s)

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Trivial change (affects only documentation or cleanup)
• Refactor (no functional changes, no api changes)

Checklist

• Tested this change with a run of GEOSgcm
• Ran the Unit Tests (make tests)

Description

In testing MAPL on Discover with GNU, it was found the ExtData2G unit tests were failing. There were two issues:

1. The overall test uses ESMF, but wasn't run with mpirun. On discover, all MPI code must be executed via mpirun
2. The test still had an issue with a couple unit tests internally not handling an expected failure.

These fixes were due to the kind help of @darianboggs and @tclune

Related Issue

[mathomp4]

Sigh. I guess it fixed in one place and broke everywhere else. I'll take a look...