Allow seekTo to go to millisecond rather than floored second

Author: mattbajorek

ios/Classes/AudioPlayer.swift

@@ -119,7 +119,7 @@ class AudioPlayer: NSObject, AVAudioPlayerDelegate {
 
     func seekTo(_ time: Int?, _ result: @escaping FlutterResult) {
         if(time != nil) {
-            player?.currentTime = Double(time! / 1000)
+            player?.currentTime = TimeInterval(time!) / 1000
             result(true)
         } else {
             result(false)