Add configuration of JupyterHub groups and shared notebook servers

[ellisonbg]

Jupyterhub now supports having single user notebook servers run as JupyterHub services and giving a group of users access to those servers. It would be great if we offered the configuration of those things in this ansible setup. Here are the examples that show how it can be done:

https://github.com/jupyterhub/jupyterhub/tree/master/examples/service-notebook

We would need:

• List of groups and users in each group
• List of shared servers, with the name of each server (URL) and the group that should be given access.

@minrk @willingc

[mathematicalmichael]

if the hub is running within a container, do you still pass the 127.0.0.1 ip address? I've been unable to get those examples you linked to working (unable to connect to the service).