Synchronize Python 3 requirements
Synchronize Python 3 requirements

We missed a few requirements in Python 3, which breaks installing
Ceilometer in Python 3 environment and therefore breaks Gnocchi.

Change-Id: I0fa6f5cad00eb3d5a645216bd96b4bba55417f88

mathslinux/ceilometer,Juniper/ceilometer,Juniper/ceilometer,openstack/aodh,idegtiarov/ceilometer,openstack/ceilometer,chungg/aodh,pczerkas/aodh,sileht/aodh,cernops/ceilometer,pkilambi/ceilometer,openstack/ceilometer,eayunstack/ceilometer,r-mibu/ceilometer,chungg/aodh,ityaptin/ceilometer,isyippee/ceilometer,eayunstack/ceilometer,pczerkas/aodh,pkilambi/ceilometer,cernops/ceilometer,maestro-hybrid-cloud/ceilometer,ityaptin/ceilometer,r-mibu/ceilometer,fabian4/ceilometer,maestro-hybrid-cloud/ceilometer,redhat-openstack/ceilometer,redhat-openstack/ceilometer,fabian4/ceilometer,isyippee/ceilometer,openstack/aodh,sileht/aodh,mathslinux/ceilometer,idegtiarov/ceilometer