Allow API to set a custom ID for server creation. (pterodactyl#187)

* Allow API to set a custom ID for server creation.

Useful when dealing with billing systems such as WHMCS

* Correct API code changes based on feedback.

Author: death-droid

app/Repositories/ServerRepository.php

@@ -88,7 +88,8 @@ public function create(array $data)
             'option' => 'bail|required|numeric|min:1|exists:service_options,id',
             'startup' => 'string',
             'custom_image_name' => 'required_if:use_custom_image,on',
-            'auto_deploy' => 'sometimes|boolean'
+            'auto_deploy' => 'sometimes|boolean',
+            'custom_id' => 'sometimes|required|numeric|unique:servers,id',
         ]);
 
         $validator->sometimes('node', 'bail|required|numeric|min:1|exists:nodes,id', function ($input) {
@@ -232,6 +233,11 @@ public function create(array $data)
             $server = new Models\Server;
             $genUuid = $uuid->generate('servers', 'uuid');
             $genShortUuid = $uuid->generateShort('servers', 'uuidShort', $genUuid);
+			
+            if (isset($data['custom_id'])) {
+                $server->id = $data['custom_id'];
+            }
+
             $server->fill([
                 'uuid' => $genUuid,
                 'uuidShort' => $genShortUuid,
@@ -994,4 +1000,4 @@ public function updateSFTPPassword($id, $password)
 
     }
 
-}
+}