Awesome tool Sam! You may want to consider having the code pull a gzip'd version of resolver-list.yml to speed things up. It's 240K uncompressed, but only ~49K compressed. And even perhaps having setup.py grab the resolver list at install instead of first run.
EDIT: You're right regarding Github serving it gzipped. You can disregard my comment on that; I was using wget for testing without specifying --header='Accept-Encoding: gzip'.
EDIT: You're right regarding Github serving it gzipped. You can disregard my comment on that; I was using wget for testing without specifying --header='Accept-Encoding: gzip'.