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: Iabf6ef5bad58d86e97989c0f245753e027897f61

openstack/openstack-ansible-apt_package_pinning,openstack/openstack-ansible-apt_package_pinning