Docker Image to build Mu AppImages

Docker image with preinstalled tooling to build Mu AppImages.

This image has been created to build the Mu AppImages via GitHub Actions CI in the Mu Editor main repository: https://github.com/mu-editor/mu/actions/workflows/build.yml

Image info

The source of truth of what's in this image is the Dockerfile, which is self contained, so it's all in a single file.

For quick reference:

• Ubuntu 16.04
• Python 3.8
• xvfb