Re-enable test_dependent_behind_dequeue

This test was already refactored for v3, but it was causing occasional
timeouts. This is a very merge-heavy test, and as such, sometimes runs
out of time when contending for resources. So we'll bump the overall
hard-timeout by 30 seconds which should prevent us from timing out at
that level, and also raise the soft wait timeout to 90 seconds for just
this test.

Change-Id: I74e54d8a7d9b813772c498ccb87fb6644b533842
diff --git a/tests/unit/test_scheduler.py b/tests/unit/test_scheduler.py
index c787f73..45b2257 100755
--- a/tests/unit/test_scheduler.py
+++ b/tests/unit/test_scheduler.py
@@ -1273,8 +1273,10 @@
         self.assertEqual(self.getJobFromHistory('project-test2').result,
                          'FAILURE')
 
-    @skip("This test generally works but times out frequently")
     def test_dependent_behind_dequeue(self):
+        # This particular test does a large amount of merges and needs a little
+        # more time to complete
+        self.wait_timeout = 90
         "test that dependent changes behind dequeued changes work"
         # This complicated test is a reproduction of a real life bug
         self.sched.reconfigure(self.config)