squash of all commits in refactor-address-controller
instead of filling in all response values, just fill in those for keys and values passed in from params; also, only geocode if the string is not empty
we were checking on district too much and in too many places
update to hobby db
remove unnecessary rake task
add ESRI terraformer library

- for ESRI JSON -> GeoJSON conversion
remove unused code
remove unused councils.geojson
fetch and convert ESRI districts, add to map
set global app.districts variable
improved code clarity + Mesa districts comment
removed apparently useless line

- district_data wasn’t set/used elsewhere
  and we set response[:in_district] later
fix bug where same lat/lng was always returned

- if the user supplied a lat/lng, use it
remove unused/commented code: getDistrictGeom()
disable some debugging logging
update readme to reflect changes to requirements
highlight selected district
Merge pull request #115 from codeforamerica/feature/remove-postgis

remove postgis requirement