Use correct flavors for centos7 and fedora23 in rax
Use correct flavors for centos7 and fedora23 in rax

The rax definitions for centos7 and fedora23 were missing both the
flavor selector and the bit that tells rax to use pvhvm.  This adds
those to both images for all 3 rax regions.

Change-Id: I64cf074424b3c8eebf67510ba91bf24f2680dd0d

Tesora/tesora-project-config,dongwenjuan/project-config,openstack-infra/project-config,openstack-infra/project-config,Tesora/tesora-project-config,dongwenjuan/project-config