display all admin fields

display all admin fields as per:

https://github.com/mapzen/pelias-openstreetmap/pull/14
https://github.com/pelias/schema/pull/17

eg:
```javascript
{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "geometry": {
        "type": "Point",
        "coordinates": [
          -73.9983442,
          40.7383652
        ]
      },
      "properties": {
        "name": "Hack Manhattan",
        "alpha3": "USA",
        "admin0": "United States",
        "admin1": "New York",
        "admin1_abbr": "NY",
        "admin2": "New York",
        "local_admin": "Manhattan",
        "locality": "New York",
        "neighborhood": "Union Square",
        "text": "Hack Manhattan, Manhattan, NY"
      }
    }
  ],
  "date": 1412337550448
}
```