Update User.php

Author: driesvints

src/Contracts/User.php

@@ -14,28 +14,28 @@ public function getId();
     /**
      * Get the nickname / username for the user.
      *
-     * @return ?string
+     * @return string|null
      */
     public function getNickname();
 
     /**
      * Get the full name of the user.
      *
-     * @return ?string
+     * @return string|null
      */
     public function getName();
 
     /**
      * Get the e-mail address of the user.
      *
-     * @return ?string
+     * @return string|null
      */
     public function getEmail();
 
     /**
      * Get the avatar / image URL for the user.
      *
-     * @return ?string
+     * @return string|null
      */
     public function getAvatar();
 }