Request: Remove Hard Coded Fonts

Hey There!
  Just started using react-color, so far it seems great.

  A minor thing, but in the ChromePicker, you have hardcoded the font-family to "Menlo" in the component style.  I can't figure out how to override it... my css style gets overridden by your component style.

Here is the offending line:

https://github.com/casesandberg/react-color/blob/3270a7f42cbfa185a03ac8d7d7bd6e7e7d3170c5/src/components/chrome/Chrome.js#L20

Maybe it was by design?  but, I don't really want to make my own just to get the component to use my font-family ;-)

Thanks!

Eric
