rely on Bower for necessary components.

This was a semi-hazardous change.

1) installed backbone.localStorage through Bower
2) removed the entire js/lib dir [which formerly had traceur/traceur.js](https://github.com/addyosmani/todomvc-backbone-es6/tree/gh-pages/js/lib) -- and everything works!
3) I noticed the bower package `es6-module-loader` ships with `es6-module-loader.js` and `traceur.js` as well-- that seems to be the traceur that was included, thus negating the need for `js/lib/traceur`.

:eyes: