update jquery and ember versions

jquery 2.1.0 -> 2.1.1
ember 1.5.1 -> 1.7.0
update firebase, emberfire, and ember data versions

Firebase's simple authentication is baked into Firebase since 1.1.0, so
we don't need the firebase-simple-login library anymore. With this came
a few API changes for authentication.
add example application for gh-pages. no auth required