Flatpak + CI devops

We are trying to provide a better development cycle for contributors, users and designers. For that, would be awesome to have a CI setup that allows:

• Have Flatpak build as part of the CI.
• Create Flatpak bundles for every commit and merge request.
• Allow parallel installation of app bundles, together with other Flatpak installations or system installations.
• Ensure the development version of the app is easily recognizable.

Read more about this at the initiative and the instructions. Me and @alatiera will help with the implementation of it. Let us know if you have any questions & thoughts.