Implement basic tests and fix schema errors

Ok, should be fixed now.

I spent half an hour, trying to fix those migration tests as well, but to no avail.

Quite a weird error as well:

PHPUnit\Framework\Exception: PHP Fatal error: Uncaught AssertionError: The container was serialized. in /var/www/html/web/core/lib/Drupal/Core/DependencyInjection/ContainerBuilder.php:88

Which is thrown, when executing the migration. I don't think this is worthwhile. Please review!

@Grevil: Please just comment out the migration tests with a link to this issue. We shouldn't delete them. perhaps someone wants to fix them in the future.

Ok, commenting these tests out, will give a warning on phpunit, because there are no existent tests in the class, but I can simply create fake tests instead.

I think it would be better to just remove the "Test" suffix or add another "Disabled" suffix to the class but this solution is also okay for me here.

Automatically closed - issue fixed for 2 weeks with no activity.