public async Task<IdentityResult> RegisterUser(UserModel userModel)
        {
            IdentityUser user = new IdentityUser
            {
                UserName = userModel.UserName
            };

            var result = await _userManager.CreateAsync(user, userModel.Password);

            return result;
        }
        public async Task<IHttpActionResult> Register(UserModel userModel)
        {
             if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

             IdentityResult result = await _repo.RegisterUser(userModel);

             IHttpActionResult errorResult = GetErrorResult(result);

             if (errorResult != null)
             {
                 return errorResult;
             }

             return Ok();
        }