Support alternative authentication schemes

[nogweii]

Github authentication is great, but not everyone has an account. I'd love to see support for a more distributed form of authentication, like OpenID.

I see you use Passport 🗽 , which includes an OpenID strategy. You could even use BrowserID (aka Mozilla Persona). To go a bit more esoteric, perhaps W3C's WebID? (I would be really surprised by that one!)