mozilla/zippy — pull request #56 by muffinresearch (2014-01-08 16:37:34+00:00)
Title: Commit node_modules

So looks like the main way to do this and remove the compiled code is to use a modified .gitignore to ignore the compiled targets. What's a bit haphazard about this is that might not be everything.

Here's the discussion with more details on the recommendation: https://groups.google.com/forum/#!topic/npm-/8SRXhD6uMmk