The old Notes Django app is the only caller of this no longer supported library. I have verified that this old app is no longer functional and is already slated to be removed as part of DEPR-18. So this commit simply removes the call to firebase-token-generator and leaves removal of the Notes app to DEPR-18.
common ------ This directory contains common code shared between LMS and CMS, such as Mako templates, CSS, and Coffescript.