func centerMapOnLocation(location:CLLocation){

        let coordinateRegion = MKCoordinateRegionMakeWithDistance(location.coordinate, regionRadius * 2 , regionRadius * 2)
        map.setRegion(coordinateRegion, animated: true)
    }

   func mapView(_ mapView: MKMapView, didUpdate userLocation: MKUserLocation){
     if let loc = userLocation.location {
        centerMapOnLocation(location: loc)
        locationManager.stopUpdatingLocation()

              }
          }