Added created_at to post_likes table (#28)

extensions/likes/migrations/2021_05_10_094200_add_created_at_to_post_likes_table.php

@@ -0,0 +1,18 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+use Flarum\Database\Migration;
+
+return Migration::addColumns('post_likes', [
+    'created_at' => [
+        'timestamp',
+        'null' => false,
+        'useCurrent' => true,
+    ],
+]);