provide setup.py for building distributions

pipenv doesn't provide its own build system, instead requiring a setup.py file to build distributions. a setup.py file can be generated with pipenv-setup sync, and will need to have its required fields (package name, version, authors, etc.) manually added.

note: pipenv-setup currently requires an older version of the vistir package, which has to be manually installed with pip install vistir==0.6.1 https://github.com/Madoshakalaka/pipenv-setup/issues/138

related: tpo/tpa/team#41034 (closed) - i can use the current source to set up the environment on weather-01, but i would prefer to install it as a wheel for the production environment