WIP: Cull idle servers

[jtpio]

Still very much of a wip.

The idea is to switch to running jupyterhub-singleuser so we can make use of the activity tracking for the notebook server.

TODO

• Start notebook server with jupyterhub-singleuser
• Switch to TmpAuthenticator
• Use named servers?

cc @yuvipanda

[jtpio]

Actually we might not need this change right now.

With #34 in and after enabling user culling with TLJH (with this fix) we should have a culling mechanism very similar to the one used for mybinder.org.

[yuvipanda]

Unfortunately that won't work, due to jupyterhub/binderhub#831. TLJH is already using the Traefik proxy, so we can't use what mybinder.org uses.

[jtpio]

Thanks @yuvipanda for the pointer, we can keep an eye on this issue.