Removed a trailing comma
Removed a trailing comma

In IE8, (once you've shimmed stuff like forEach), this causes an extra word `undefined` to be added to the uncountable rules. Removing the trailing comma fixes this.

I'm guessing IE8 support is the least of your concerns but as this seems like a trivial change it'd be great if you would consider merging it.
blakeembrey/pluralize,MikaAK/pluralize