Merge pull request #20 from S-anasol/patch-1

Avoid curl exception

Author: JoshuaEstes

src/Http/Driver/CurlDriver.php

@@ -34,6 +34,7 @@ public function __destruct()
     {
         if (null !== self::$ch) {
             curl_close(self::$ch);
+            self::$ch = null; // Nulling to avoid calling curl_close again
         }
     }