Add trigger capability on github pr review

A github pull request review is a new type of event that happens when
user provides a review of a pull request
https://developer.github.com/v3/pulls/reviews

It will create an event
https://developer.github.com/v3/activity/events/types/#pullrequestreviewevent
sent to the webhook. Allow filtering on submitted or dismissed actions
and the state of the review of approved, comment, or request_changes.

Signed-off-by: Jesse Keating <omgjlk@us.ibm.com>
Change-Id: If94c2fe8adbe18fa7f426d5462559ba24963424c
diff --git a/tests/unit/test_github_driver.py b/tests/unit/test_github_driver.py
index a1a05e0..f2a6e5b 100644
--- a/tests/unit/test_github_driver.py
+++ b/tests/unit/test_github_driver.py
@@ -177,6 +177,21 @@
         self.assertEqual(2, len(self.history))
         self.assertEqual(['other label'], C.labels)
 
+    @simple_layout('layouts/reviews-github.yaml', driver='github')
+    def test_review_event(self):
+        A = self.fake_github.openFakePullRequest('org/project', 'master', 'A')
+        self.fake_github.emitEvent(A.getReviewAddedEvent('approve'))
+        self.waitUntilSettled()
+        self.assertEqual(1, len(self.history))
+        self.assertEqual('project-reviews', self.history[0].name)
+        self.assertEqual(['tests passed'], A.labels)
+
+        # test_review_unmatched_event
+        B = self.fake_github.openFakePullRequest('org/project', 'master', 'B')
+        self.fake_github.emitEvent(B.getReviewAddedEvent('comment'))
+        self.waitUntilSettled()
+        self.assertEqual(1, len(self.history))
+
     @simple_layout('layouts/dequeue-github.yaml', driver='github')
     def test_dequeue_pull_synchronized(self):
         self.executor_server.hold_jobs_in_build = True