Re-add testinfo.py into Beaker.

This was moved from beaker-server into rhts-python in commit
3c3d63012a6d23f7. We are re-adding it to avoid having a
BuildRequires on rhts-python.

Bug: 1067273
Change-Id: Ib5bf0a55a7bf46a87b24f05b34e1c3915abaa9f7