Fix race in test_queue_rate_limiting_dependent

The simultaneous release of two merge jobs each with two dependent
jobs could result in the 4 dependent jobs arriving in AABB order
rather than the expected ABAB order.  Wait between releases of
the merge jobs to ensure the expected order.

The orderedRelease method is updated to facilitate this.

Change-Id: Ibe5435e43a88ce2dd93bca96e221d91b8779f1f8
2 files changed