S3 helper for copying an S3 object from a source location to the current bucket.
s3.copyObject(source, destination, acl, [headers], callback)
This helper does not re-upload the object. It uses the PUT Object - Copy method via the x-amz-copy-source HTTP header and the x-amz-metadata-directive HTTP header for copying the source metadata.
You need the read privilege for the source object.