The global upper constraints repo will no longer track py2 packages,
meaning upper constraints for the py2.7 runtime will need to be handled
locally.
This adds an in-repo file for upper constraints enforcement using the
last py27 constraints from openstack/requirements to validate
functionality.
Change-Id: I624f914c6155178cbe474f1eae2871e2aef721eb
Signed-off-by: Sean McGinnis <sean.mcginnis@gmail.com>