Adding delete restore instance tests

- The backup test is leaving an instance around
- This test will make sure to delete it

Part of bug # 1187133

Change-Id: Ie946cf531c1b8a3c8001e605e427a84791e3e4e5
Adding Exists Event Publishing

    TaskManager periodically sends notifications for active instances

Implements: blueprint notification-exists-event

Change-Id: If9ec0a6b89ee28c550297e5a7450b0b927e034f2
Merge "Adding delete restore instance tests"
Merge "Adding Exists Event Publishing"