OAuth authentication

[andreterron]

This would allow users to have an authentication method that's simpler that user/password

Some things to keep in mind:

• Do the users need to create their own app, or can they use a central Mainframe app?
• If they need to create their own app, is that more seamless than username/password? Ensure the app setup process is clear enough.

Option: https://www.hello.coop/