updated readme.txt

git-svn-id: https://plugins.svn.wordpress.org/wp-invites/trunk@1041047 b8457f37-d9ea-0310-8a92-e5e31aec5664
updated readme.txt

git-svn-id: https://plugins.svn.wordpress.org/wp-invites/trunk@1041049 b8457f37-d9ea-0310-8a92-e5e31aec5664