dist/react-md-editor.js error 

Hi @JedWatson
First of all thanks so such , It's a cool editor built in react. 
I want to use dist/react-md-editor.js with webpack externals , but I find an error "react-md-editor.js:1 Uncaught Error: Cannot find module 'classnames' " , react-md-editor.js miss 'classnames' code.
