Update README.md

See #486

Author: mevdschee

README.md

@@ -1,6 +1,6 @@
 # PHP-CRUD-API (v2)
 
-Single file PHP 7 script that adds a REST API to a MySQL 5.5 InnoDB database. PostgreSQL 9.1 and MS SQL Server 2012 are fully supported. 
+Single file PHP 7 script that adds a REST API to a MySQL 5.6 InnoDB database. PostgreSQL 9.1 and MS SQL Server 2012 are fully supported. 
 
 NB: This is the [TreeQL](https://treeql.org) reference implementation in PHP.