Update composer.json

README.md

@@ -5,6 +5,7 @@
 **Requires at least:** 3.6  
 **Tested up to:** 6.0  
 **Stable tag:** 1.4.3  
+**Requires PHP:** 5.6  
 **License:** GPLv2 or later  
 **License URI:** http://www.gnu.org/licenses/gpl-2.0.html