Merge remote-tracking branch 'origin/esd-spack-installation' into...

Merge remote-tracking branch 'origin/esd-spack-installation' into VT-70-function-Migrate-Spack-env-setup-into-ESD-repo-with-buildcache

# Conflicts:
#	esd/spack_manager/SpackManager.py
#	esd/tests/spack_from_scratch_test.py