updated the readme

Author: hemant7405

readme.txt

@@ -3,7 +3,7 @@ Contributors: brainstormforce
 Donate link: https://www.paypal.me/BrainstormForce
 Tags: schema markup, structured data, rich snippets, schema.org, Microdata, schema
 Requires at least: 3.7
-Tested up to: 5.6
+Tested up to: 5.7
 Stable tag: 1.6.4
 License: GPLv2 or later
 License URI: http://www.gnu.org/licenses/gpl-2.0.html