Gerrit approval records have a 'by' field

We need to look one level deeper.

Change-Id: I81dbc316ded86739fd7d5413beb7a51a4e57e4f5
diff --git a/tests/test_scheduler.py b/tests/test_scheduler.py
index a74ad17..9787ae1 100755
--- a/tests/test_scheduler.py
+++ b/tests/test_scheduler.py
@@ -221,11 +221,13 @@
         approval = {'description': self.categories[category][0],
                     'type': category,
                     'value': str(value),
-                    'username': username,
-                    'email': username + '@example.com',
+                    'by': {
+                        'username': username,
+                        'email': username + '@example.com',
+                    },
                     'grantedOn': int(granted_on)}
         for i, x in enumerate(self.patchsets[-1]['approvals'][:]):
-            if x['username'] == username and x['type'] == category:
+            if x['by']['username'] == username and x['type'] == category:
                 del self.patchsets[-1]['approvals'][i]
         self.patchsets[-1]['approvals'].append(approval)
         event = {'approvals': [approval],