Auto-reconfigure after change-merged event

Rather than respond to the internal report of a change merging,
respond to the change-merged event from the trigger, that way
we will still reconfigure when a change is merged out-of-band.

Change-Id: I684273cad495da7b937f7b80917c7869a0e173d3
diff --git a/tests/base.py b/tests/base.py
index 66fd85a..c81ac7d 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -263,6 +263,16 @@
                  "comment": "This is a comment"}
         return event
 
+    def getChangeMergedEvent(self):
+        event = {"submitter": {"name": "Jenkins",
+                               "username": "jenkins"},
+                 "newRev": "29ed3b5f8f750a225c5be70235230e3a6ccb04d9",
+                 "patchSet": self.patchsets[-1],
+                 "change": self.data,
+                 "type": "change-merged",
+                 "eventCreatedOn": 1487613810}
+        return event
+
     def addApproval(self, category, value, username='reviewer_john',
                     granted_on=None, message=''):
         if not granted_on: