Gesture Handler for DVParallaxView

DVParallaxViewPanHandler.m

#pragma mark - Gesture handler

- (void)panHandler:(UIPanGestureRecognizer *)pan {
    CGPoint translation = [pan translationInView:self];
    [self setContentOffset:CGPointMake(self.contentOffset.x + translation.x,
                                       self.contentOffset.y - translation.y)];
    
    [pan setTranslation:CGPointZero inView:self];
}