Added new models

lib/models/ServerVersion.php

@@ -0,0 +1,25 @@
+<?php
+declare(strict_types=1);
+namespace Gitea\Models;
+
+/**
+ * Warps the version of the Gitea server.
+ */
+class ServerVersion {
+
+  /**
+   * @var string The version number.
+   */
+  public $version = '';
+
+  /**
+   * Creates a new server version from the specified JSON map.
+   * @param object $map A JSON map representing a server version.
+   * @return static The instance corresponding to the specified JSON map.
+   */
+  static function fromJson(object $map): self {
+    return new static([
+      'version' => isset($map->version) && is_string($map->version) ? $map->version : ''
+    ]);
+  }
+}