Publishing our dazel image

[while-false]

I think it would be a great idea if we could periodically (rebuild) and publish the dazel docker image that can be obtained from Dockerfile.dazel. It would allow us to easily base other images off this image.

I imagine that we would want the image tagged both with a :latest as well as timestamp (e.g. :YYMMDD).

As the dockerfile is public, the image could too be published publicly, though I don't see this as a hard requirement.