Set up cron in Dockerfile

[valearna]

Add cron to the Dockerfile and start it when the docker container starts

[valearna]

@azurebrd there's a new crontab file under /curation where to add crontabs. I've also moved the setup shell commands executed when the container starts from the Dockerfile to a separate script (container_startup_setup.sh)

[azurebrd]

That's great, thanks @valearna ! I'll probably ask you later on about how to use it.

[valearna]

Copy crontab file using a volume to allow edits from inside docker and avoid rebuilding the image when modified

[valearna]

done