Fix to support WooCommerce 2.1.x

git-svn-id: https://plugins.svn.wordpress.org/duracelltomi-google-tag-manager/trunk@867218 b8457f37-d9ea-0310-8a92-e5e31aec5664
Preparing for v0.7.1 release

git-svn-id: https://plugins.svn.wordpress.org/duracelltomi-google-tag-manager/trunk@867220 b8457f37-d9ea-0310-8a92-e5e31aec5664