Development versions of logstash Docker images

Are there any development versions of the Logstash Docker images hosted on the Elastic Docker repository? By development versions I mean the resulting image that would be generated if you build from the source Dockerfile https://github.com/elastic/logstash/blob/master/Dockerfile.

The context for this question is I'm working with a legacy Logstash install that has an RSpec test suite for the filter configurations and at some point the packaged Logstash stopped shipping with the development tools included. I was able to build an image and get the old tests to run (and mostly fail) inside the new container, but if possible I'd like to use a "semi-official" development image if such a thing exists.

You can get nightlies at (currently):

docker.elastic.co/logstash/logstash:7.0.0-alpha1-SNAPSHOT

You still have to add in the dev tools (sorry), but the image will be current with the master branch of Logstash.