Add missing pauses in reconfiguration tests

We need to wait for zuul to settle before we can presume that
the new configuration is in place.

Change-Id: I47354c98325df12cf8180c77e6f34f738874ecc7
diff --git a/tests/unit/test_v3.py b/tests/unit/test_v3.py
index e566479..3a4e164 100644
--- a/tests/unit/test_v3.py
+++ b/tests/unit/test_v3.py
@@ -116,6 +116,7 @@
             dict(name='project-test2', result='SUCCESS', changes='1,1')])
 
         self.fake_gerrit.addEvent(A.getChangeMergedEvent())
+        self.waitUntilSettled()
 
         # Now that the config change is landed, it should be live for
         # subsequent changes.
@@ -164,6 +165,7 @@
         self.assertHistory([
             dict(name='project-test2', result='SUCCESS', changes='1,1')])
         self.fake_gerrit.addEvent(A.getChangeMergedEvent())
+        self.waitUntilSettled()
 
         # The config change should not affect master.
         B = self.fake_gerrit.addFakeChange('org/project', 'master', 'B')