Docker build and Kubernetes hosting

[nagyv]

Hi,

I forked mygpo to add a Dockerfile and updated its settings.py a bit to better support Kubernetes-based deployments (it adds more flexibility using environment variables with django-configurations. I'd love to contribute these back to the project if there is interest in them.

Are you open to these changes?

[JeanFred]

See also #355

[nagyv]

A working version is available at https://gitlab.com/nagyv/gpodder

Let me know how can I contribute the changes back here!

[nagyv]

Closing as a duplicate of #355