Switch to oauth

This change switches to oauth for user authentication, removing these dependencies while adding none:

• shibd (and its... interesting... config)
• httpd (for compatibility with shibd)
• nginx

To replace nginx, the L1CE api takes over all routing, and generates its SSL keys on the fly.

Large portions of the configuration is now gone, what remains has been centralized in a yaml file.
Logic has been added that a different config file can be loaded based on where L1CE is deployed (hostname based).

PM2 has been replaced by systemd