Add all js files to precompile rake task

The way the app is configured with RequireJS, rake assets:precompile won't compile those JS files, so we have to explicitly add them. If we don't precompile them, Heroku won't find them and the app will crash.
Remove unused stylesheets
Merge pull request #190 from codeforamerica/fix-assets-precompilation

Fix assets precompilation