Add style attribute to package.json

Signed-off-by: Nicole Sullivan <nsullivan@pivotal.io>

package.json

@@ -2,6 +2,7 @@
   "name": "font-awesome",
   "description": "The iconic font and CSS framework",
   "version": "4.3.1",
+  "style": "css/font-awesome.css",
   "keywords": ["font", "awesome", "fontawesome", "icon", "font", "bootstrap"],
   "homepage": "http://fontawesome.io/",
   "bugs": {