I updated my ipython notebook gist, but why didn’t nbviewer update?

This is an nbviewer
FAQ.

Basically it takes about 10 minutes to update, but if you want to
force it, you can add ?flush_cache=true to the nbviewer URL.

So try doing this:

http://nbviewer.ipython.org/gist/rsignell-usgs/aa12c2b5e8a448bda780?flush_cache=true