Add default credentials

Signed-off-by: Xheni Myrtaj <myrtajxheni@gmail.com>

Author: xh3n1

RESTAPIphpListClient.php

@@ -10,8 +10,8 @@
 
 //Please replace the following values with yours.
 $loginname = 'admin';
-$password = 'admin1234';
-$base_uri = 'http://10.211.55.4:81/lists/base/public/api/v2';
+$password = 'phplist';
+$base_uri = 'http://example.com/lists/base/public/api/v2';
 
 try {
     $response = $client->request('POST', $base_uri . '/sessions', [