fix-tests

Author: Darshan808

tests/test_zmq_shell.py

@@ -227,6 +227,7 @@ def test_display_stored_in_history(self):
         mock_shell.display_pub._in_post_execute = False
 
         self.disp_pub.shell = mock_shell
+        self.disp_pub.store_display_history = True
 
         data = {"text/plain": "test output"}
         self.disp_pub.publish(data)