Add call_and_ignore_notfound_exc to Keystone base

Keystone base class methods don't include
call_and_ignore_notfound_exc during cleanup. If a test
deletes something, cleanup causes a failure.

Change-Id: Ic36237f28188188eb1de8ce1e5c80c3b4a618ca0
Closes-Bug: #1665475
1 file changed