[chore] Rename pytest teardown methods from deprecated teardown to teardown_method (#768)

Author: jonathanedey

tests/test_messaging.py

@@ -1586,7 +1586,7 @@ def test_aps_alert_custom_data_override(self):
 
 class TestTimeout:
 
-    def teardown(self):
+    def teardown_method(self):
         testutils.cleanup_apps()
 
     def _instrument_service(self, url, response):

tests/test_token_gen.py

@@ -853,5 +853,5 @@ def _instrument_session(self, app):
         request.session.mount('https://', testutils.MockAdapter(MOCK_PUBLIC_CERTS, 200, recorder))
         return recorder
 
-    def teardown(self):
+    def teardown_method(self):
         testutils.cleanup_apps()