title: How to update the marker position on google map by latitude and longitude values
body: <p>I am new to iOS Swift. I recently started working on <code>GMSMaps</code>. In my code I am able to get the <code>latitude</code> and <code>longitude</code> values of source and destination to find the direction and I am also able to add the marker to map. But, I want to change the position of marker based on changing the source and destination values. When I tried to change source/destination ,then again one more marker is adding to maps. I don't want to add one more marker, I just want to move the previous marker to updated location . If any one gives solution it would be so great.</p>
  
  <p>This is my code which I have written to add marker for source and destination. I have written this code in <code>didSelectRowAtIndexPath</code> method of tableView</p>
  
  <pre><code>let centerr = CLLocationCoordinate2D(latitude: lat, longitude: lon)
  var camera = GMSCameraPosition.camera(withLatitude: lat, longitude: lon, zoom: 10);
  self.googlemapsview.camera = camera
  var marker = GMSMarker(position: centerr)
  print("Latitude :- \(lat)")
  print("Longitude :-\(lon)")
  marker.map = self.googlemapsview
  </code></pre>