fix pytest warning

keycloak/connection.py

@@ -60,6 +60,9 @@ class ConnectionManager(object):
 
             self._s.mount(protocol, adapter)
 
+    def __del__(self):
+        self._s.close()
+
     @property
     def base_url(self):
         """ Return base url in use for requests to the server. """

keycloak/tests/test_connection.py

@@ -156,6 +156,7 @@ class TestConnection(unittest.TestCase):
         with mock.patch.object(KeycloakOpenID, "__init__", return_value=None) as mock_keycloak_open_id:
             with mock.patch("keycloak.keycloak_openid.KeycloakOpenID.token", return_value=fake_token):
                 with mock.patch("keycloak.connection.ConnectionManager.__init__", return_value=None) as mock_connection_manager:
+                    with mock.patch("keycloak.connection.ConnectionManager.__del__", return_value=None) as mock_connection_manager_delete:
                         server_url = "https://localhost/auth/"
                         username = "admin"
                         password = "secret"
@@ -187,3 +188,4 @@ class TestConnection(unittest.TestCase):
                                                                    headers=expected_header,
                                                                    timeout=60,
                                                                    verify=False)
+                        mock_connection_manager_delete.assert_called_once_with()