provide both benchmark and test model from command line
provide both benchmark and test model from command line

do not rely on the hard-coded "testing/check" folder to point to the
location of the "benchmark model".

pierrelb/RMG-Py,nyee/RMG-Py,nickvandewiele/RMG-Py,pierrelb/RMG-Py,nickvandewiele/RMG-Py,nyee/RMG-Py