Update readme.txt

git-svn-id: https://plugins.svn.wordpress.org/transdirect-shipping/trunk@1027753 b8457f37-d9ea-0310-8a92-e5e31aec5664
Update to v 1.2

git-svn-id: https://plugins.svn.wordpress.org/transdirect-shipping/trunk@1027754 b8457f37-d9ea-0310-8a92-e5e31aec5664