Create Github Demo Page

[elwayman02]

This PR updates the Demo app and integrates ember-cli-github-pages to make it easy to publish a demo page for this repo.

Example: http://elwayman02.github.io/e3/

In order to publish the demo page for this repo after merging, run the following commands:

$ ember install ember-cli-github-pages
$ git checkout --orphan gh-pages && rm -rf `ls -a | grep -vE '\.gitignore|\.git|node_modules|bower_components|(^[.]{1,2}$)'` && git add -u && git commit -m "initial gh-pages commit"
$ git checkout master
$ ember github-pages:commit --message "Initial Demo App Release"
$ git push --set-upstream origin/gh-pages

Once pushed, you should be able to access the demo page at http://ravellaw.github.io/e3

After the initial release, you should only have to do the following:

$ ember github-pages:commit --message "Demo app update message"
$ git push

More info: https://github.com/poetic/ember-cli-github-pages

[ghost]

[spencer516]

Awesome! Will do this right now. :)