Support a hosted version

[anishathalye]

Right now, there's no hosted version of Gavel. If someone wants to use the system, they have to run their own server (or use Heroku) - this requires some level of technical sophistication.

It could be neat to modify the system to allow for a hosted version (and then we could have a default hosted version that people could use if they don't want to run their own).

This would involve adding user (organizer) accounts and stuff (and then supporting multiple events running at the same time), setting up a system where people can create events at eventname.<domain> or <domain>/event, and a bunch of other changes like this.

This would probably be a pretty substantial project.