WIP - change to mongo
nicer formatting of addresses after geocoding

Also saving zip to DB
Reverse relationship on Locations and Reports

Locations now has a property called 'reports', which is an array of Report
objectIds. This allows us to get the number of reports for a property in a
single query, or the reports themselves with a single mongoose .populate() call.
Allow comments on reports

See github issue #13
Debugging cleanup
Create pins and update popups when user reports location

See Github issue #10