improve catalog deployment

[alee]

1. is there a distinction between staging and prod deployment? if so, have deploy.sh take an optional argument "prod | staging" to distinguish between those, at the moment it always runs ./compose prod which raises the question of why there is even a staging.yml file
2. deploy.sh should rebuild the django image and update existing dependent images as well
3. update docs at https://github.com/comses/catalog/wiki/Deployment
4. consider adding the app version to footer so we know what's actually running

[alee]

https://docs.docker.com/engine/swarm/swarm-tutorial/rolling-update/