fix typo

models/response.go

@@ -49,7 +49,7 @@ func (r *Response) AddUnsubscription(sub Subscription) {
 }
 
 // Add new data publish to response
-func (r *Response) AddUPublish(pub Publish) {
+func (r *Response) AddPublish(pub Publish) {
 	r.Publish = append(r.Publish, pub)
 }