Investigate jupyter-scheduler

[dometto]

In VRE Lab, it would be nice to have a userfriendly of running notebooks as (long-running) background jobs. This can be achieved with papermill, but there is also a web 'GUI' extension:

https://github.com/jupyter-server/jupyter-scheduler

• Investigate by pip installing this into a JupyterLab environment (start a VRE Lab and test it).
• If satisfactory, ensure it is installed by default (edit the jupyterhub role).
• Add documentation.

[dometto]

One cool thing would be to see if we could hook up jupyter-scheduler and the SRC messaging API