District Instance
list: Return all districts, which can filter ballot items.
retrieve: Return a specific district, which can filter ballot items.
GET /api/districts/2915/?format=api
http://michiganelections.io/api/districts/2915/?format=api", "id": 2915, "category": "Intermediate School District", "name": "Gratiot-Isabella Regional Education Service" }{ "url": "