Added support for CF.DEL command (#1080)

Co-authored-by: Vladyslav Vildanov <vladyslavvildanov@Vladyslav-Vildanov-MacBook-Pro.local>

src/ClientInterface.php

@@ -71,6 +71,7 @@ use Predis\Response\Status;
  * @method int               cfadd(string $key, $item)
  * @method int               cfaddnx(string $key, $item)
  * @method int               cfcount(string $key, $item)
+ * @method int               cfdel(string $key, $item)
  * @method int               cfexists(string $key, $item)
  * @method int               cfmexists(string $key, ...$item)
  * @method array             cfinfo(string $key)