Presently, tempest in the integrated build is installed from PyPI, but without
constraints. This means the version installed may not be what is expected (as
we're currently seeing in the stable/pike branch).
This commit removes the tempest_git_* overrides from
playbooks/defaults/repo_packages/openstack_testing.yml, which results in
tempest getting installed from PyPI but with constraints applied.
Change-Id: I014201129b4d6b47ec45ff6239287623123a1595
61e8553ae3