Remove lodash as a dependency.
Remove hardcoded link to css/app.css.

This is now specified in the assets.json file.
Remove dependency on lodash for iterating through assets.

This is in response to point 9 on the following article:
http://engineering.linkedin.com/nodejs/blazing-fast-nodejs-10-performance-tips-linkedin-mobile

We want to default to native JavaScript when possible. Also, use
Object.keys instead of a for ... in loop because of this jsperf:
http://jsperf.com/for-in-versus-object-keys-foreach/6
Add css/app.css in assets.json.
Remove use of Array.forEach for native for loop.

This is in response to jsperf results that show Object.keys + for
loop is faster than for ... in loop and Array.forEach:
http://jsperf.com/for-in-versus-object-keys-foreach/6
http://jsperf.com/array-foreach-vs-for-loop/5