District Instance
list: Return all districts, which can filter ballot items.
retrieve: Return a specific district, which can filter ballot items.
GET /api/districts/2870/?format=api
http://michiganelections.io/api/districts/2870/?format=api", "id": 2870, "category": "Ward", "name": "City of Muskegon, Ward 4" }{ "url": "