Add cron container in global docker compose

[kirtangajjar]

All global services are being managed through docker-compose. Only cron container is being managed through docker run command.

Cron container should also run through docker-compose.

[LotusJeff]

I think this is a symptom of Cron being a run command. Running Cron on Ubuntu. Have one site running. Created a second site. Deleted a second site. ee-cron-scheduler no-longer is running. reboot the server. ee-Cron-scheduler does not come up.

[LotusJeff]

Temp work around for stopped ee-cron-scheduler at: https://community.easyengine.io/t/ee-cron-scheduler-shut-down-after-ee-site-delete-command-all-ee-cron-jobs-no-longer-run/12576/2