Build docker images for Elixir release candidate builds?

[Philip Ross]

Elixir v1.12.0-rc.1 (and v1.12.0-rc.0 ) have been release in the past few weeks. Would it make sense to publish these docker images. I would love an easy way to test if an upcoming release will break anything in our project, and the easiest way to do that would be to just run all of our ci tests with the new image. However since Bob currently doesn't publish docker images for Elixir release candidates, I can't easily test my project against upcoming elixir versions. I know that I can clone bob and then build the images locally, but thats quite a bit of work and then that doesn't even consider that the image is only local to my computer, so I'd either have to recreate my ci tests locally, or push my locally created image to my own docker registry. Either way it would really nice if Bob builds these release candidate versions.

I can understand not wanted to spam too many tags, but it seems like it does build Erlang release candidates. Perhaps pushing these release candidate builds to a new docker repo (say hexpm/elixir-edge, or something) would be a good compromise.