readme.txt: update

git-svn-id: https://plugins.svn.wordpress.org/premium-testimonials/trunk@782812 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme.txt: update

git-svn-id: https://plugins.svn.wordpress.org/premium-testimonials/trunk@782815 b8457f37-d9ea-0310-8a92-e5e31aec5664