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

            IdentityResult result = await this.userManager.CreateAsync(user, userModel.Password);

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

            IdentityResult result = await this.repository.RegisterUser(userModel);

            IHttpActionResult errorResult = this.GetErrorResult(result);

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

            return this.Ok();
        }
        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();
        }