use labels for all intermediate slurm containers?

[jspaaks]

e.g.

• xenon-slurm:abstract instead of xenon-slurm-abstract
• xenon-slurm:ssh instead of xenon-slurm-ssh
• xenon-slurm:fixture instead of xenon-slurm-fixture

might make it a little bit clearer what is in the stack while keeping the dockerhub search result list that users get when searching for 'slurm' small.

[sverhoeven]

For automated builds on Docker Hub, repository links can only link another Docker Hub repository.
To have automated builds triggered by it's parents each parent must be a Docker Hub repository.

So your label proposal will make it impossible to have the automated builds run in the right order.