Remove dispatch_async calls to main queue

Due to the changes made in #77

RCTVideo.m

@@ -261,13 +261,11 @@ static NSString *const statusKeyPath = @"status";
 
 - (void)attachListeners
 {
-  dispatch_async(dispatch_get_main_queue(), ^{
   // listen for end of file
   [[NSNotificationCenter defaultCenter] addObserver:self
                                            selector:@selector(playerItemDidReachEnd:)
                                                name:AVPlayerItemDidPlayToEndTimeNotification
                                              object:[_player currentItem]];
-  });
 }
 
 - (void)playerItemDidReachEnd:(NSNotification *)notification
@@ -287,23 +285,17 @@ static NSString *const statusKeyPath = @"status";
 - (void)setResizeMode:(NSString*)mode
 {
   _resizeMode = mode;
-  dispatch_async(dispatch_get_main_queue(), ^{
   _playerLayer.videoGravity = mode;
-  });
 }
 
 - (void)setPaused:(BOOL)paused
 {
   if (paused) {
     [self stopProgressTimer];
-    dispatch_async(dispatch_get_main_queue(), ^{
     [_player pause];
-    });
   } else {
     [self startProgressTimer];
-    dispatch_async(dispatch_get_main_queue(), ^{
     [_player play];
-    });
   }
 
   _paused = paused;
@@ -323,7 +315,6 @@ static NSString *const statusKeyPath = @"status";
     CMTime tolerance = CMTimeMake(1000, timeScale);
 
     if (CMTimeCompare(current, cmSeekTime) != 0) {
-      dispatch_async(dispatch_get_main_queue(), ^{
       [_player seekToTime:cmSeekTime toleranceBefore:tolerance toleranceAfter:tolerance completionHandler:^(BOOL finished) {
         [_eventDispatcher sendInputEventWithName:RNVideoEventSeek body:@{
           @"currentTime": [NSNumber numberWithFloat:CMTimeGetSeconds(item.currentTime)],
@@ -331,7 +322,6 @@ static NSString *const statusKeyPath = @"status";
           @"target": self.reactTag
         }];
       }];
-      });
 
       _pendingSeek = false;
     }
@@ -365,23 +355,17 @@ static NSString *const statusKeyPath = @"status";
 - (void)applyModifiers
 {
   if (_muted) {
-    dispatch_async(dispatch_get_main_queue(), ^{
     [_player setVolume:0];
     [_player setMuted:YES];
-    });
   } else {
-    dispatch_async(dispatch_get_main_queue(), ^{
     [_player setVolume:_volume];
     [_player setMuted:NO];
-    });
   }
 
   [self setResizeMode:_resizeMode];
   [self setRepeat:_repeat];
   [self setPaused:_paused];
-  dispatch_async(dispatch_get_main_queue(), ^{
   [_player setRate:_rate];
-  });
 }
 
 - (void)setRepeat:(BOOL)repeat {