Fix broken test.
Fix broken test.

This was my fault.  I made the change (from document_id to policy_id) in 4849c19aed60b7e107b49c8a3c27d1ae2ba01eb4 but then rebased on top of 1487a5a30a546c6fd9474c3527d1bd1e464b6327 without running the tests before pushing.

alphagov/whitehall,ggoral/whitehall,askl56/whitehall,YOTOV-LIMITED/whitehall,YOTOV-LIMITED/whitehall,robinwhittleton/whitehall,robinwhittleton/whitehall,askl56/whitehall,ggoral/whitehall,YOTOV-LIMITED/whitehall,hotvulcan/whitehall,ggoral/whitehall,alphagov/whitehall,alphagov/whitehall,hotvulcan/whitehall,robinwhittleton/whitehall,askl56/whitehall,askl56/whitehall,robinwhittleton/whitehall,ggoral/whitehall,hotvulcan/whitehall,hotvulcan/whitehall,YOTOV-LIMITED/whitehall,alphagov/whitehall