Add SubsetOptionParser unit tests to make check target.
Add SubsetOptionParser unit tests to make check target.

Change-Id: I95284872b34960069427153344cd1f6c785d0bd2
Signed-off-by: Christopher M. Cantalupo <9cf3ecca60a3dd7112ab0e7250bedb8a752e3958@intel.com>

geopm/geopm,cmcantalupo/geopm,geopm/geopm,cmcantalupo/geopm,cmcantalupo/geopm,cmcantalupo/geopm,cmcantalupo/geopm,geopm/geopm,geopm/geopm,geopm/geopm