[Fact]
public async Task Test_Create_User()
{
    var options = new DbContextOptionsBuilder<TinRollContext>()
        .UseInMemoryDatabase(databaseName: "Create_User")
        .Options;

    var newUser = new User
    {
        Email = "test@email.com",
        UserName = "userName"
    };

    int ? userId = null;
    //create user in memory database
    using (var context = new TinRollContext(options))
    {
        var userRepository = new UserRepository(context);
        userId = await userRepository.CreateUserAsync(newUser);
    }

    Assert.NotNull(userId);
    //check to make sure it exists
    using (var context = new TinRollContext(options))
    {
        var userCount = await context.Users.CountAsync();
        Assert.Equal(1, userCount);
    }
}