Fix time formatting (#28)

Displayed as 02:010 before

lib/src/utils.dart

@@ -7,13 +7,13 @@ String formatDuration(Duration position) {
   var minutes = seconds ~/ 60;
   seconds = seconds % 60;
 
-  final hoursString = hours > 10 ? '$hours' : hours == 0 ? '00' : '0$hours';
+  final hoursString = hours >= 10 ? '$hours' : hours == 0 ? '00' : '0$hours';
 
   final minutesString =
-      minutes > 10 ? '$minutes' : minutes == 0 ? '00' : '0$minutes';
+      minutes >= 10 ? '$minutes' : minutes == 0 ? '00' : '0$minutes';
 
   final secondsString =
-      seconds > 10 ? '$seconds' : seconds == 0 ? '00' : '0$seconds';
+      seconds >= 10 ? '$seconds' : seconds == 0 ? '00' : '0$seconds';
 
   final formattedTime = '${hoursString == '00' ? '' : hoursString +
       ':'}$minutesString:$secondsString';