Fix CI

[evrardjp]

The CI with molecule is always flakey due to systemd in docker. I am tired of maintaining this, and I am looking for a sustainable solution.

I used to have vagrant, which was also tedious to setup in new environments where virtualbox was not allowed.

I am looking for an alternative that doesn't need a lot of maintainance. (And, if possible, is portable)

[evrardjp]

I got a first draft with lxd that worked out of the box, and is simple. I am using it for local testing now. I need to extend the coverage and cleanup our old testing. If anyone is against the idea, please tell us here and propose an alternative :)