Omnomic was envisioned as an engine and set of design patterns for quick prototyping and development (in the game design sense, not the software sense) of turn-based games.
The code, as it is now, is largely the result of one particular quick, hacky prototype for a game called One Last Job, built on Google's App Engine.
Forking that project here has probably broken some things, but the repo has to start somewhere.
There are some external libraries necessary, which can be installed by running
pip install -t lib -r reqs.txt
(The demo also has an assets directory for the card art, which is omitted here.)