Switch to devstack-plugin-ceph-tempest-py3 for ceph
Switch to devstack-plugin-ceph-tempest-py3 for ceph

We dropped the tempest-full python2 job from our zuul config awhile
back with change I93e938277454a1fc203b3d930ec1bc1eceac0a1e. Since we
track ceph job health by how its failure rate compares with our basic
tempest full job, this updates our config to run the python3 version
of the ceph job by default and drops the python2 version of the job.

Change-Id: I92e01b896751f7f29a0b2b826c33cb2c74b8ced4

openstack/nova,openstack/nova,klmitch/nova,mahak/nova,klmitch/nova,rahulunair/nova,klmitch/nova,openstack/nova,rahulunair/nova,rahulunair/nova,mahak/nova,klmitch/nova,mahak/nova