Como configurar o Play!2.5 com ReactiveMongo

play.modules.enabled += "play.modules.reactivemongo.ReactiveMongoModule"
mongodb.uri = "mongodb://localhost:27017/demodb"

class MongoUserDao @Inject() (val reactiveMongoApi: ReactiveMongoApi)
extends UserDao {
//  val users = reactiveMongoApi.db.collection[JSONCollection]("users") -- old API
//   def find(userId:UUID):Future[Option[User]] =
//    users.find(Json.obj("id" -> userId)).one[User]  -- old code

  def usersF = reactiveMongoApi.database.map(_.collection[JSONCollection]("users"))  //new API

  def find(userId:UUID):Future[Option[User]] = for {
    users <- usersF
    user <- users.find(Json.obj("id" -> userId)).one[User]
  } yield user     // new code
}