Wrong URL for SonarQube badges
The SonarQube badges URLs in the README are incorrect, while the one from Gitlab's project are right.
I suspect it is due to 3736723b
IMHO, it is better to keep the Maven ID (org.orekit:orekit) as key. It is a pain that Gitlab CE does not offer the ability to run a merge-request of a fork in the context of the upstream project