Docker image outdated

[ChristianMoesl]

It is confusing, that the Docker image with latest does not represent the source of the master branch. Can someone build a new Docker image from HEAD? This is especially important, because there is a fix missing in there (c6671d4).

[Gatsby-Lee]

I built with the latest in my forted repo.
in case, you're interested.
https://hub.docker.com/repository/docker/wowbro/gatsbyjs-docker/general