Scaling websockets

Horizontally scaling with websockets is difficult but possible:

- https://github.com/django/channels/issues/960
- https://channels.readthedocs.io/en/1.x/deploying.html#scaling-up
- https://www.excella.com/insights/scaling-django-channels-with-docker
- https://avilpage.com/2018/05/deploying-scaling-django-channels.html

this won't help w/ scalability but we should try using this:
- https://github.com/github/stable-socket