Updated compat info

git-svn-id: https://plugins.svn.wordpress.org/event-calendar-ticketing/trunk@815277 b8457f37-d9ea-0310-8a92-e5e31aec5664
Updated README

git-svn-id: https://plugins.svn.wordpress.org/event-calendar-ticketing/trunk@815286 b8457f37-d9ea-0310-8a92-e5e31aec5664