make a copy of license file in root directory with a filename github will detect
make a copy of license file in root directory with a filename github will detect

Signed-off-by: Alex Kofke <c196266af12125980d5e66676ed65acbc1f52c32@gmail.com>

etomica/etomica,ajschult/etomica,etomica/etomica,etomica/etomica,ajschult/etomica,ajschult/etomica