MAINT: Put Py-ART under pip git installs, removed xsapr_clutter and added gcc. For cmac, we want the most recent updates of Py-ART so it has been moved under pip installs. xsapr_clutter is no longer needed, because it is within the cmac code now, and gcc package is now required for a proper install due to cython and cartopy.
MAINT: Put Py-ART under pip git installs, removed xsapr_clutter and
added gcc.
For cmac, we want the most recent updates of Py-ART so it has been moved
under pip installs. xsapr_clutter is no longer needed, because it is
within the cmac code now, and gcc package is now required for a proper
install due to cython and cartopy.

zssherman/cmac2.0,EVS-ATMOS/cmac2.0,EVS-ATMOS/cmac2.0,zssherman/cmac2.0