Geocode cache route

NOT READY TO MERGE

* geocoding with Google
  * no api key required
  *  2,500 requests/day
* cache is generic and can be reused - backed by a postgres table
* naive caching based on the query param: "Charlotte, NC", "Charlotte NC", "charlotte, nc", "charlotte nc" will each be seen as unique.
* Google's api supports many languages, so when we begin work on localization we should incorporate it into geocoding as well.
* Next steps:
  * ~~Update `app.utils.geocode` to handle the new response.~~
  * ~~Test on staging~~
  * ~~figure out why the build is failing intermittently~~ the geocoder gem seems to have been the culprit.