Add browse page

A few components here:

- the actual browse page
- a new model to contain a summary for each address, which is viewed on the browse page
- a script to populate the db with the above summaries (probably run once/day by cron job in production)
- tests!
My thinking with this was to have everything denormalized in one "summary" table. We still have business names and types separately stored in the table with all business licenses / can query against that if we want.