Docker hub (https://hub.docker.com/r/mitre/caldera) is outdated

[sudobinbash]

Describe the bug

• The Dockerhub packaging of Caldera is outdated (3y old)
  https://hub.docker.com/r/mitre/caldera
• It seems like its published by Mitre (https://hub.docker.com/u/mitre)

To Reproduce
Steps to reproduce the behavior:
The https://hub.docker.com/r/mitre/caldera readme and update status will show the gaps.

Expected behavior
Ideally, the hub would be synced with the master/main branch in this repo.
(nice to have) The docker setup would be incorporated into the Dockerfile (instead of using git, pip, manually)

Screenshots
N/A

Desktop (please complete the following information):
N/A

Additional context

Just a big shout out for this amazing project... Thank you so much for building this (I'd be happy to send a PR and fix the dockerhub issue, but AFAIK this cannot be done from the repo itself and requires some extra steps in docker.com I have no access to :( )

[github-actions]

Looks like your first issue -- we aim to respond to issues as quickly as possible. In the meantime, check out our documentation here: http://caldera.readthedocs.io/