Consider tagging some images with build date

[GCHQDeveloper314]

When pushing new images to GitHub containers with tags which replace tags on previously pushed images, the old images remain but without any tags:

On Docker Hub the old untagged containers are not visible.

For some containers (at least Accumulo & Hadoop), a new image with potentially identical tags is built upon each release. This will result in an increasing number of untagged images.

To fix this we could add an extra tag with version plus build date. This would allow old revisions to be used and prevent any images from showing as untagged.