Fix flake8 error (#933)

Not sure why this is now an error but it's blocking changes.

Author: omgjlk

tests/integration/test_github.py

@@ -461,7 +461,7 @@ def test_octocat(self):
         with self.recorder.use_cassette(cassette_name):
             o = self.gh.octocat()
             assert o is not None
-            assert o is not ""
+            assert o != ""
             o = self.gh.octocat(say)
             assert say in o