Configuring database username and password in Compound JS project (MongoDB)

I have started using CompoundJS with MongoDB as database. I know i should do the host configuration in /config/database.json, but not sure how i should add username/password for database configuration.

I tried to add username/password like below, but its not functional

{ "development":
  { "driver":   "mongoose"
  , "url": "mongodb://localhost/stats_development",
    "username": "admin",
    "password": "123456"
  }
, "test":
  { "driver":   "mongoose"
  , "url": "mongodb://localhost/stats_test",
    "username": "admin",
    "password": "123456"
  }
, "production":
  { "driver":   "mongoose"
  , "url": "mongodb://localhost/stats_production",
    "username": "admin",
    "password": "123456"
  }
}