remove unused reponse field

chatState_test.go

@@ -13,7 +13,6 @@ func TestChatState(t *testing.T) {
 		"txt":  "What is your date of birth?",
 		"icon": "/mnt/data/abc.jpg",
 	}
-	s.response = "somexml less than 2048 bytes"
 
 	//save
 	err := s.Save()
@@ -29,7 +28,6 @@ func TestChatState(t *testing.T) {
 	AssertEqual(t, m.Data["txt"], s.Data["txt"], "Message[txt] should be equal")
 	AssertEqual(t, m.Data["icon"], s.Data["icon"], "Message[icon] should be equal")
 	AssertEqual(t, m.OpenID, openID, "openID should be "+openID)
-	AssertEqual(t, m.response, "", "response should be empty")
 	AssertEqual(t, m.Procedure, procedure, "procedure should be "+procedure)
 	AssertEqual(t, m.Data["txt"], s.Data["txt"], "Message[txt] should be equal")
 	AssertEqual(t, m.Data["icon"], s.Data["icon"], "Message[icon] should be equal")