Fix client tests due to changes in code from 'mistral' repository

-Removing 'start-task' parameter from test workbooks
-Lowercase key section names in workbooks from unit tests
-Rename 'test_cli_acitons' to 'test_cli_actions'
-Fix CLI test 'test_task_list' due to changes in
https://review.openstack.org/#/c/121818/

Change-Id: I8ace89b460c3c72cdac3c3f42684fe1e8b6ad5de