- add class to test when erp5_web, which provides category_expiration_workflow, is installed
 - remove not needed login method, ERP5TypeTestCase provides very good one


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@32765 20353a03-c40f-0410-a6d1-a30d3c3de9de