added single class for get_trending_tags api call

Author: t3ran13

Commands/Single/GetTrendingTagsCommand.php

@@ -0,0 +1,10 @@
+<?php
+
+
+namespace GrapheneNodeClient\Commands\Single;
+
+
+class GetTrendingTagsCommand extends CommandAbstract
+{
+    protected $method = 'get_trending_tags';
+}