Update bundle

I'm preparing to update to nanoc 3.7.0 today, so might as well get the
little updates over with first.
Upgrade to nanoc 3.7.0

The upgrade to nanoc 3.7.0 is complete. No output changes. Hooray for
semantic versioning!
Enable Rouge and deprecate CodeRay

Finally, switching to Rouge (1.4.0) for syntax highlighting. Known bug:
the comment line in the js example page is getting highlighted
incorrectly. I'm investigating. It doesn't seem to be a problem with
Rouge, since rougify highlights it correctly.