store all admin fields

store all admin fields on record as per https://github.com/pelias/schema/pull/17

eg:
```javascript
{
  "_index": "pelias",
  "_type": "osmnode",
  "_id": "address-node-42752609",
  "_version": 1,
  "found": true,
  "_source": {
    "name": {
      "default": "2103 Saint Paul Avenue"
    },
    "type": "node",
    "center_point": {
      "lat": 40.8541193,
      "lon": -73.8298641
    },
    "alpha3": "USA",
    "admin0": "United States",
    "admin1": "New York",
    "admin1_abbr": "NY",
    "admin2": "Bronx",
    "local_admin": "Bronx",
    "locality": "New York",
    "neighborhood": "Pelham Bay",
    "suggest": {
      "input": [
        "2103 saint paul avenue"
      ],
      "payload": {
        "id": "osmnode\/address-node-42752609",
        "geo": "-73.82986410000001,40.8541193"
      },
      "output": "2103 Saint Paul Avenue, Bronx, NY",
      "weight": 4
    }
  }
}
```