Support Zuul as a Gerrit user equivalent to Jenkins

Change-Id: I72c76fc1891b56aeb827a86e33f594324dce26bc

elastic_recheck/elasticRecheck.py

@@ -216,7 +216,7 @@ class Stream(object):
             return False
 
         username = event['author'].get('username', '')
-        if (username != 'jenkins'):
+        if (username not in ['jenkins', 'zuul']):
             return False
 
         if not ("Build failed" in

recheckwatchbot.yaml

@@ -18,7 +18,7 @@ channels:
 messages:
   # | means don't fold newlines, > means do
   found_bug: |
-    I noticed jenkins failed, I think you hit bug(s):
+    I noticed Zuul failed, I think you hit bug(s):
 
     %(bugs)s
   footer: >-
@@ -32,5 +32,5 @@ messages:
     us classify these issues so that they can be part of Elastic Recheck
     http://status.openstack.org/elastic-recheck/
   no_bugs_found: >-
-    I noticed jenkins failed, refer to:
+    I noticed Zuul failed, refer to:
     http://docs.openstack.org/infra/manual/developers.html#automated-testing