A fix was merged in Tempest so we need to update run_tests.sh to stop
pinning Tempest. Because of that we need to promote the repo otherwise
the downstream CI job will never update the packages.
After this patch got merged, we'll come back on the static URL.
- Unpin Tempest on CentOS
- Pin Tempest on Ubuntu (Ocata not packaged yet)
Change-Id: I2330faf700230fe40119169347ad72f8332d0821