fixed 2.6 compat with order_by test

Author: BlackVegetable

keen/tests/client_tests.py

@@ -501,7 +501,7 @@ def test_order_by(self, get):
         limit = 2
         order_by = {"property_name": "result", "direction": keen.direction.DESCENDING}
         resp = keen.count(collection, timeframe="today", group_by="number", order_by=order_by, limit=limit)
-        self.assertTrue("https://api.keen.io/3.0/projects/{}/queries/count".format(keen.project_id) in
+        self.assertTrue("https://api.keen.io/3.0/projects/{0}/queries/count".format(keen.project_id) in
                          get.call_args[0][0])
         self.assertEqual(2, get.call_args[1]["params"]["limit"])
         self.assertEqual(collection, get.call_args[1]["params"]["event_collection"])