title: Can't extract geo keys (nodejs and mongo)
body: <p>I am working with nodejs (expres framwork) and mongodb with mongoose. And I am trying to save the geolocation coordinates to my db.</p>
  
  <p>This is how my schema looks like:</p>
  
  <pre><code>//defining a schema
  var TopicSchema = mongoose.Schema({
     topicTitle: String,
     topicDescription: String,
     topicDateCreated: { 
        type: Date, 
        default: Date.now 
     },
     fbId: String,
     twId: String,
     location: {
        type: {
          type : String
        },
     coordinates: [Number]
    }
  });
  
  TopicSchema.index({ location: '2dsphere' });
  var Topic = restful.model('topic', TopicSchema);
  Topic.methods(['get', 'put', 'post', 'delete']);
  Topic.register(app, '/data');
  </code></pre>
  
  <p>Via socket.io I pass the data to the server. The server receives the data but upon saving it I get the following error: </p>
  
  <pre><code>MongoError: Can't extract geo keys
  </code></pre>