So, what about resizing animated GIFs?

Nobody has claimed this yet.

Hi,
I've used this Filter to resize images in custom FilterLoader
Maybe the problem is in my mac?

```
public function apply(ImageInterface $image)
{
$isAnimated = count($image->layers()) > 1;

if($isAnimated === true){
$image->layers()->coalesce();
/** @var ImageInterface $frame */
foreach ($image->layers() as $frame){
$frame->resize($this->size, $this->filter);
}
$image->layers()->merge();

} else {
$image->resize($this->size, $this->filter);
}

return $image;
}
```

With this config

```
liip_imagine:
driver: imagick
filter_sets:
default:
jpeg_quality: 90
png_compression_level: 9
animated: true
```

But, in the result i got the image with bad quality and not animated :) . Maybe I did something wrong?

Start at the custom FilterLoader's apply method and reproduce the supplied configuration with the imagick driver and animated: true. Check the resulting GIF's frame count and quality against the input; done means resizing preserves the animation and produces acceptable quality.

Written by the indexing model from the issue text.