Remove unnecessary loop in github test

This loop serves no purpose, it just makes the test take a tad bit
longer.

Change-Id: If37ecbd297c8f35d9b8cb7d2136acfe7bec19f05
diff --git a/tests/unit/test_github_requirements.py b/tests/unit/test_github_requirements.py
index 34da88f..f125d1e 100644
--- a/tests/unit/test_github_requirements.py
+++ b/tests/unit/test_github_requirements.py
@@ -240,13 +240,10 @@
 
         # The first negative review from derp should not cause it to be
         # enqueued
-        for i in range(1, 4):
-            submitted_at = time.time() - 72 * 60 * 60
-            A.addReview('derp', 'CHANGES_REQUESTED',
-                        submitted_at)
-            self.fake_github.emitEvent(comment)
-            self.waitUntilSettled()
-            self.assertEqual(len(self.history), 0)
+        A.addReview('derp', 'CHANGES_REQUESTED')
+        self.fake_github.emitEvent(comment)
+        self.waitUntilSettled()
+        self.assertEqual(len(self.history), 0)
 
         # A positive review from derp should cause it to be enqueued
         A.addReview('derp', 'APPROVED')