Add a CI build with USE_IMATH_HALF enabled
Add a CI build with USE_IMATH_HALF enabled

Signed-off-by: Dan Bailey <39b6ae1dd30d9ab3cd77a2d084b277520f14c203@ilm.com>

dreamworksanimation/openvdb,dreamworksanimation/openvdb,dreamworksanimation/openvdb,dreamworksanimation/openvdb