Add tests

[vadorovsky]

For now my suggestion would be to have two kinds of tests

• unit tests (with some mocks, to not have to load actual BPF programs when running as user)
• integration tests with runc/podman, something local and lightweight (requiring root, doing actual BPF operations)

For future we might consider also some E2E tests with Kubernetes.

[briandowns]

Unity for C is a really nice and easy to use unit testing library. Not sure if you've used it. If not, here's an example. https://github.com/briandowns/libspinner/blob/master/tests/tests.c

[vadorovsky]

I didn't. I only used https://developer.gnome.org/glib/stable/glib-Testing.html once and had a look at the selftests in the Linux kernel.