Merge pull request #2567 from mattermost/css-webpack-improvments

Moving from scss vendors folder to NPM.

webapp/package.json

@@ -10,6 +10,7 @@
     "compass-mixins": "0.12.7",
     "fastclick": "1.0.6",
     "flux": "2.1.1",
+    "font-awesome": "4.5.0",
     "highlight.js": "9.2.0",
     "intl": "1.1.0",
     "jasny-bootstrap": "3.1.3",