Version-specific tags

[embray]

Currently the only tags for this image available on Docker Hub are "latest", and some really old, presumably obsolete one.

It would be wonderful if there were tags for specific GAP versions (4.10.2, 4.11.0, etc.). The Dockerfile seems almost but not quite set up for that, since "gap-4.11" is still hard-coded in part of the URL.

[sadikkuzu]

At the end of March 2021, two versions were published:

• version-4.11.0 : gapsystem/gap-docker:version-4.11.0
• version-4.11.1 : gapsystem/gap-docker:version-4.11.1

https://hub.docker.com/r/gapsystem/gap-docker/tags