Note the removal of after_s3_sync in middleman-s3_sync v4.0
Note the removal of after_s3_sync in middleman-s3_sync v4.0

Per the middleman-s3_sync changelog for version 4.0.0, the after_s3_sync hook has been removed since Middleman v4 no long supports hooks. https://github.com/fredjean/middleman-s3_sync/blob/master/Changelog.md#v400
andrusha/middleman-cloudfront