Change record status: 
Description: 

Switching to using branch labels for pift_retest_versions will ensure that the proper tests are run after the current development version of a project changes. This will be particularly helpful for keeping up with RTBC retesting for core's 6 month release cycle.

Production outage: No
Change affects: PIFT
Deployment schedule: week of 2017-08-21
Backout plan: revert or fix in place