Remove unused serialization functions

src/action/adduser.ts

@@ -1,6 +1,6 @@
 /*
  * server component for the TimeLimit App
- * Copyright (C) 2019 Jonas Lochmann
+ * Copyright (C) 2019 - 2020 Jonas Lochmann
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -54,15 +54,6 @@ export class AddUserAction extends ParentAction {
     }
   }
 
-  serialize = (): SerializedAddUserAction => ({
-    type: 'ADD_USER',
-    name: this.name,
-    userType: this.userType,
-    userId: this.userId,
-    password: this.password,
-    timeZone: this.timeZone
-  })
-
   static parse = ({ name, userId, userType, password, timeZone }: SerializedAddUserAction) => (
     new AddUserAction({
       name,