public string PostUser(UserDTO userDto)
 {
     if (usersService.Save(userDto))
     {
         return("User saved!");
     }
     else
     {
         return("User is not saved!");
     }
 }
        public IHttpActionResult Create(UserDTO userDTO)
        {
            ResponseMessage response = new ResponseMessage();

            if (userDTO.Validate() == false)
            {
                response.Code = 400;
                response.Body = "Invalid data - User has not been saved";

                return(Json(response));
            }
            if (_service.Save(userDTO))
            {
                response.Code = 201;
                response.Body = "User has been saved.";
            }
            else
            {
                response.Code = 200;
                response.Body = "User has not been saved.";
            }

            return(Json(response));
        }