Use upper constraints for all tox targets
Use upper constraints for all tox targets

With the implementation of https://review.openstack.org/388087 all
tox targets may now use upper constraints.

Change-Id: If6c0cc075bc495d259b2e344cfa1050f092770b7

juledwar/openstack-ansible-os_ironic,juledwar/openstack-ansible-os_ironic