Feature/pure jdbc integration

This merge request will look a bit sloppy because the old atomium-server-jdbc module was renamed to atomium-server-slick and a new module was added with the old name (atomium-server-jdbc). Because of the overlap in certain file names, the merge request will consider this as changed files instead of entirely new files. That said, I think it is best to review the code in your IDE and only look at the module atomium-server-jdbc. Comments can still be left on GitHub.

In addition, the module rename and adding of a new module with the old name confused IntelliJ. I had to clear my caches before the project was listed as it should. Removing the .idea folder and recreating the project didn't do the job. Everyone will be affected once this branch is merged in develop. You're warned :)