public async Task Can_Register_User()
        {
            //arrange
            var mock        = new Mock <IAccountMongoService>();
            var userService = new AccountMongoController(mock.Object);
            var user        = new RegisterModel {
                Email = "*****@*****.**", Password = "******", ConfirmPassword = "******"
            };
            //act
            await userService.Register(user);

            //assert
            mock.Verify(c => c.RegisterUser(It.Is <RegisterModel>(s => s.Email == "*****@*****.**")), Times.Once());
            Assert.Equal("*****@*****.**", user.Email);
        }