add the password with in "mongo": { }
so your config.json would look like this
{ "url": "http://xxx:4567", "secret": xxx, "database": "mongo", "port": 4567, "mongo": { "host": "127.0.0.1", "port": "27017", "username": "mongodb", "password": "mymongopwd", "database": "0" } }
