FYI: outdated case-studies 1house + 1node now reproducible

[ojdo]

Just as a heads up: I was triggered by a request to make those old, archived case study runnable. I first tried to port them to current urbs, but realised that the simpler approach would be to add a environment.yml file with the state of all dependencies then. I pushed the file to both branches, including instructions on how to create + activate that "urbs-2017" virtual environment.