[Feature] Create a "pull" target to let someone update their containers from upstream

[mcdan]

Even when using :latest in a container tag, compose does not automatically pull new versions. You must use docker-compose pull. I propose adding a mirror make pull that will update the containers, this will not be part of the make quick-start to ensure we don't overwrite containers someone is working on locally.

Docker-compose issue stating how you must use pull: docker/compose#3574

[jthomas]

Great idea - I had this exact issue today where the images were out of date compared to the configuration files. Came here to raise the issue and found this...