Fix node server side react rendering. Window undefined

When compiling react components server side, window function throws error:

/app/components/react-draggable.js:62
var isTouchDevice = 'ontouchstart' in window // works on most browsers
                                      ^
ReferenceError: window is not defined
update conditional to check for window
Merge pull request #30 from DavidWells/master

Fix for node server side react rendering. window undefined