Publish new gh-pages with every release

* Updates the gh_pages folder so it can stand alone
* Use release-it to push to gh-pages on every release

Other small tweaks:

* Use grunt-release-it as a wrapper for release-it
* Move bower dependencies to vendor/ folder

@dylnuge @bigsley @yayalice
This is just how `grunt-release-it` leaves the file, I guess. I'm going to leave it like this, it's not a big deal.