public async Task<IHttpActionResult> RegisterUser([FromBody]RegisterUserModel registerUserModel)
 {
     var service = new AuthenticationService();
     var user = await service.RegisterUser(registerUserModel.UserName, registerUserModel.Password, registerUserModel.FullName);
     return Ok(user);
 }
 public async Task<IHttpActionResult> AuthenticateUser(string userName, string password)
 {
     var service = new AuthenticationService();
     var user = await service.AuthenticateUser(userName, password);
     return Ok(user);
 }