use a more relatable starting point

[tobyhodges]

From feedback received during pilot lesson at CC@Home2020: the lesson material could be improved by starting with a more authentic project/code, e.g. a relatively simple Numpy analysis. It was suggested that this would be more likely to reflect the experience of the target audience, and could make the value of tools such as virtualenv/a requirements.txt file more immediately apparent later in the lesson.

[willfurnass]

At the same time, someone commented that they liked that the example package contained very little real code as it helped them focus on the package/repo structure.

However, I do think creating a dependency on numpy really helps with illustrating the value of virtualenvs/requirements.txt (and dependencies encoded in setup.py, if covered at some point). Looks like that has been addressed since CC@Home2020 given the rendered content at https://carpentries-incubator.github.io/python-packaging-publishing/04-environments-virtualenv/index.html