Updated phpCS version to 5.6, this was done for all bundled commands at once

Author: janw-me

phpcs.xml.dist

@@ -42,7 +42,7 @@
 
 	<!-- For help understanding the `testVersion` configuration setting:
 		 https://github.com/PHPCompatibility/PHPCompatibility#sniffing-your-code-for-compatibility-with-specific-php-versions -->
-	<config name="testVersion" value="5.4-"/>
+	<config name="testVersion" value="5.6-"/>
 
 	<!-- Verify that everything in the global namespace is either namespaced or prefixed.
 		 See: https://github.com/WordPress-Coding-Standards/WordPress-Coding-Standards/wiki/Customizable-sniff-properties#naming-conventions-prefix-everything-in-the-global-namespace -->