Fix tempest git repos usage for old OSP's
Fix tempest git repos usage for old OSP's

When --setup git is used, we need to download
tempest from different repos/branches depending
on the openstack version.

Openstack version should be defined as int, becasue
the openstack_release filter returns int value.

Otherwise the default repo will be always used.

Change-Id: Ib3b879b89cefbd140d4f5ae5fa7f8dda7d187432

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared