[CONTINUUM-2713] remove DMI from Maven 1

Add another test for adding from the project group page

git-svn-id: https://svn.apache.org/repos/asf/continuum/branches/CONTINUUM-2713@1548101 13f79535-47bb-0310-9956-ffa450edef68
[CONTINUUM-2713] remove DMI from deleting a notifier from group

Add missing test

git-svn-id: https://svn.apache.org/repos/asf/continuum/branches/CONTINUUM-2713@1548102 13f79535-47bb-0310-9956-ffa450edef68