JupyterHubs for management of Econ-ARK/Dolo/related trainings

We have hub.econ-ark.org available to use for providing a standard environment for workshops. We should be able to setup a new machine quickly if and when the need arises for a workshop.

Start by reviewing the available hub.econ-ark.org environment and identifying how it is currently configured for workshops. Clarify the required Econ-ARK, Dolo, and training environments, then define what a repeatable new-machine setup must cover; done means the setup process can be followed when another workshop is needed.

Written by the indexing model from the issue text.