Replace MongoDB with Postgres

This commit outlines all the changes that were necessary to make the
app work with Postgres and ActiveRecord.
Change permissions for setup_prod_db

So it can run on Heroku.
Specify app when fetching SEARCHBOX_URL
Remove redundant message about elasticsearch index
Update travis to use Postgres
Remove hyphen from test database name

Travis didn't like that.
Create a separate database config file for travis

http://docs.travis-ci.com/user/using-postgresql/
Remove redundant message from reset script
Remove psql line from travis
Put bootstrap-sass in assets group

Travis runs bundle without assets, but bootstrap-sass requires sass-rails, which is in assets.
Tell Travis to create test DB
Add DB rake tasks to travis
Add important note about incompatibility with Elasticsearch 1.1.0
Upgrade Rails from 3.2.17 to 4.0.4
Remove hours field from phone object in sample_data

The app currently doesn't use that field, so pushing to Heroku will display warnings about not being able to mass assign protected attributes for Phone: hours.
Add specs for accessing locs, orgs & categories by their old slug
Add endpoints for new models to support admin interface

With the move from Mongo to Postgres, the admin interface had to change the way it communicates with the API to update the data, so the API had to add endpoints for all the new models.
Reload the location for Travis

There is one test that depends on Elasticsearch updating its index, which sometimes doesn't happen fast enough. Maybe introducing this location reload will help.
Merge pull request #147 from codeforamerica/postgres

Mongo to Postgres migration
Remove database.yml from .gitignore

It's needed to be able to install the repo locally, and it doesn't contain any sensitive info.