Rejigger the Readme

Update the order of the Heroku instructions.
Merge pull request #181 from codeforamerica/readme-update

Rejigger the Readme
Add style guide gem
Add helpers to style guide
Add short title
Refactor application layout
Extract mapbox ID assignment to an external file
Extract common layout elements as partials
Add style guide entry for header
Add foundation
Add Compass
Add jasmine tests
Prune comments from newrelic.yml
Add Teaspoon for javascript specs
Add geojson rendering for locations; use url_for to generate location urls

* Also save fixtures for locations
Restyle landing page as style guide elements
Collapse partials; use jbuilder partial for FeatureCollection on location index
Remove mapbox requirements
Remove map; refactor answer to no longer create answers
Add test coverage for map