Improve trigger base test case coverage
Improve trigger base test case coverage

This patch some test cases to improve the test coverage for the trigger
base module.

Change-Id: I4cffaeb49ceb9b80190c5c101f318ce70b797c63

openstack/senlin,openstack/senlin,Alzon/senlin,stackforge/senlin,Alzon/senlin,openstack/senlin,tengqm/senlin-container,stackforge/senlin,tengqm/senlin-container