[TestMethod]
public void CreateUserSuccess()
{
    var userName = "testuser";
    var password = "testpwd";
    var email = "testmail@test.com";

    var mock = new Mock<IAccountService>()
    .Setup<MembershipCreateStatus>(x => x.CreateUser(userName, password, email))
    .Returns(MembershipCreateStatus.Success);

    mock.Verifiable();
}