public function upload($path, $target)
{
$finfo = new \Finfo(FILEINFO_MIME_TYPE);
return $this->client->putObject(array('Bucket' => $this->bucket, 'Key' => $this->computePath($target), 'SourceFile' => $path, 'ContentType' => $finfo->file($path), 'ACL' => $this->config('acl', 'public-read')));
}