Clarify that contributions are expected to be Apache 2.0
Clarify that contributions are expected to be Apache 2.0

jpritikin/OpenMx,mhunter1/OpenMx,jpritikin/OpenMx,jpritikin/OpenMx,jpritikin/OpenMx,mhunter1/OpenMx,jpritikin/OpenMx,jpritikin/OpenMx,mhunter1/OpenMx,mhunter1/OpenMx,mhunter1/OpenMx,mhunter1/OpenMx