upd tag in readme

git-svn-id: https://plugins.svn.wordpress.org/iconic-navigation/trunk@975705 b8457f37-d9ea-0310-8a92-e5e31aec5664
tagging ver 1.1.5

git-svn-id: https://plugins.svn.wordpress.org/iconic-navigation/trunk@975706 b8457f37-d9ea-0310-8a92-e5e31aec5664