Avoid attempting to retranspile javascript

I don't really know much about browserify transforms... (Read as, I don't know anything about browserify transforms :-p )

But this seems to work as a "fix" (it might be more of a workaround...) for #27 

The code base I'm working on works with this code with watchify, and nothing seems to have degraded?

This may be a terrible solution (as I don't really know what the actual problem is...) but it was enough for me to migrate to browserify 7.0.0, so thought it might be helpful? :-s