Wait until wait_for turrets are connected and ready

def wait_turrets(self, wait_for):
        """Wait until wait_for turrets are connected and ready
        """
        print("Waiting for %d turrets" % (wait_for - len(self.turrets_manager.turrets)))

        while len(self.turrets_manager.turrets) < wait_for:
            self.turrets_manager.status_request()

            socks = dict(self.poller.poll(2000))

            if self.result_collector in socks:
                data = self.result_collector.recv_json()
                self.turrets_manager.process_message(data)

                print("Waiting for %d turrets" % (wait_for - len(self.turrets_manager.turrets)))