Integrate SANBI-SA/irods_docker for persistent storage

[pvanheus]

Hi there

At a recent code jamboree we created https://github.com/SANBI-SA/irods_docker that splits the Docker iRODS catalogue server into multiple containers linked using docker-compose, with a data-only container to facilitate persistent storage of iRODS data and configuration. I'm interested in contributing to this to irods/contrib if you are interested.