Replace __sleep with __serialize for object serialization

Author: Arshid

src/Illuminate/Queue/Middleware/RateLimited.php

@@ -147,7 +147,7 @@ protected function getTimeUntilNextRetry($key)
      *
      * @return array
      */
-    public function __unserialize(array $data)
+    public function __serialize()
     {
         return [
             'limiterName' => $this->limiterName,

tests/Integration/Cache/Fixtures/Unserializable.php

@@ -6,7 +6,7 @@
 
 class Unserializable
 {
-    public function __unserialize(array $data)
+    public function __serialize()
     {
         throw new Exception('Not serializable');
     }