464 refactor color variables

This resolves #464. Things to note:
* The first commit is me removing `config/application.example.yml` cause I was being a newb, but I put it back later.
* Similar thing with the cassettes.
* Added Guard-Livereload and Rack-Livereload to the Gemfile for live reloading of browser during development. Is this an issue? I know you're trying to reduce dependencies, but it doesn't add any additional steps to setting up the dev environment, everything is handled by bundler.

The color variable names all follow the conventions we discussed in [#464](https://github.com/codeforamerica/ohana-web-search/issues/464). Let me know if you see any further issues that need to get addressed before you merge this.