GeoJSON output for iss-now

[jseppi]

What do you think about formatting your iss-now response as GeoJSON (http://geojson.org/), or perhaps offering a slightly different endpoint such as /iss-now.geojson that does so? Since GeoJSON has become more or less the de facto way of presenting spatial data in JSON it would make the API more accessible to other applications.

Example output:

{
  "type": "Feature",
  "geometry": {
    "type": "Point",
    "coordinates": [-75.0436504109561, -46.338151423860474]
  },
  "properties": {
    "timestamp": 1412347452
  }
}

I would not mind doing the implementation if you are amenable to pull requests.