Add more tests.

Add two tests:
 * Changes behind failed changes get retested
 * Shared change queues

Also, add the ability to simulate that a job for a change failed.

Change-Id: Ia266a9a6a8920ef49b24025f8109c4414c563e8c
Reviewed-on: https://review.openstack.org/10578
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins
2 files changed