Document Dockerfile

[1084565]

In this repo's docker branch we're having a Dockerfile. It is a copy (no changes!) of the original in devops-docker-images/cm-client

Tasks:

• [ ] protect the docker branch (just like master)
• [ ] set up docker build
• [ ] delete Dockerfile from devops/docker-images

Question:

• Do we want Dockerfile linting (Travis?)

[1084565]

Please review. Dockerfile (hidden in the docker branch has no docuemntation so far and no build + the branch is not protected.

[1084565]

Please review @radsoulbeard