A better way of getting _id at the end of node.self.

I'm getting `{name: 'Testing Testsson', _id:NaN}` when calling ` db.insertNode({name: 'Testing Testsson'}, function(err, res) { console.log(res) })`.

I'm running `node-neo4j v2.0.0-RC1` and `neo4j v1.9.5`.

This way, just getting all the digits from the end of the `node.self` seems like a better idea.

Would you agree?