Support R2DBC connection

Hi,

First, I would like to share I really like this project and use it a lot in project for my db testing, so thanks !

I would like to know, or request, if the support of R2DBC connection is planned?
R2DBC is starting to be more and more stable and simple to implement, so using it for perf/integration and be able to use `assertj-db` for tests is something very important.

Thanks, and happy new year by the way ;)