public async Task<ActionResult> Login(LoginViewModel model, string returnUrl)
        {
            if (ModelState.IsValid)
            {
                var user = await Task.Run(() => _usersRepository.GetUserByAppLogin(model.Login, model.Password));

                if (user != null)
                {
                    OwinAuthHelper.SignIn(Request.GetOwinContext(), user);
                    return Redirect(returnUrl ?? Url.Action("Index", "Game"));
                }
                ModelState.AddModelError("", "Incorrect Username or password");
                return View();
            }
            return View();
        }
        public async Task<ActionResult> SignUp(LoginViewModel model, string returnUrl)
        {
            var newUser = await _usersRepository.CreateUser(model.Login, model.Password);

            if (newUser != null)
            {
                OwinAuthHelper.SignIn(Request.GetOwinContext(), newUser);
                return Redirect(returnUrl ?? Url.Action("Index", "Game"));
            }
            return View();
        }