Add test for X served by response header

tests/integration/test_integration_service_subscriptions.py

@@ -14,3 +14,4 @@ def test_read_service_subscription(account, service_subscription, service_subscr
     resource = account.service_subscriptions.read(service_subscription.entity_id)
     asserts.assert_resource(resource)
     asserts.assert_resource_params(service_subscription,service_subscription_params)
+

tests/integration/test_response_headers.py

@@ -0,0 +1,5 @@
+
+def test_x_served_by(api):
+    response = api._rest.get(url=api.admin_api_url + '/accounts')
+    assert response.status_code == 200
+    assert "X-Served-By" not in response.headers