add logic to store event modification and deleted event

storage/mongodb.go

@@ -120,3 +120,13 @@ func (s MongoDBStorage) AddSubscription(eventid string, subscription Subscriptio
 	_, err := collection.UpdateOne(context.TODO(), filter, push)
 	return err
 }
+
+func (s MongoDBStorage) UpdateEvent(event Event) error {
+	collection := s.Client.Database(s.DbName).Collection(s.Collections["events"])
+	if _, err := collection.ReplaceOne(context.TODO(), bson.M{"_id": event.ID}, event); err != nil {
+		fmt.Println(err)
+		return err
+	}
+
+	return nil
+}