Add database test to travis build for RMG-Py repo
Add database test to travis build for RMG-Py repo

'make test-database' was previously only tested in the RMG-database
test repo, but this increases safety by putting it onto the RMG-Py repo
as well

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