ipatests: tasks: add user_del
Add an "ipa user-del" frontend to tasks.py.
Related: https://pagure.io/freeipa/issue/8536
Signed-off-by: François Cami <fcami@redhat.com>
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>
Reviewed-By: Kaleemullah Siddiqui <ksiddiqu@redhat.com>