after(function(done){
    mongo.connect(db, function (err, db) {
      if(err) return done(err);

      db.dropDatabase(function (err, res){
        if(err) return done(err);

        console.log("result:", res); // output = "result: true" but the database is really still there.
        db.close(done);
      });
    });
 });