DEMO
class SimpleCoordinator extends SubscribableActor {
val feeder = context.system.actorOf(TwitterFeederActor.props())
feeder ! AddUser("Newscred_Devs_P")
feeder ! SubscribeReceiver(self)
val scraper = context.system.actorOf(Props[ScraperActor])
receiveBuilder += {
case SendStatus(status: Status) =>
scraper ! ExtractTopics(status.getURLEntities()(0).getURL(), scraper)
}
}