Update repository base code to be cleaner and make use of PHP 7 features

app/Repositories/Eloquent/ServerVariableRepository.php

@@ -1,11 +1,4 @@
 <?php
-/**
- * Pterodactyl - Panel
- * Copyright (c) 2015 - 2017 Dane Everitt <dane@daneeveritt.com>.
- *
- * This software is licensed under the terms of the MIT license.
- * https://opensource.org/licenses/MIT
- */
 
 namespace Pterodactyl\Repositories\Eloquent;
 
@@ -15,7 +8,9 @@ use Pterodactyl\Contracts\Repository\ServerVariableRepositoryInterface;
 class ServerVariableRepository extends EloquentRepository implements ServerVariableRepositoryInterface
 {
     /**
-     * {@inheritdoc}
+     * Return the model backing this repository.
+     *
+     * @return string
      */
     public function model()
     {