Destroy user's sessions when (Bug 1328705)

- users change his/her password
- admins delete the user's account

Change-Id: Id88207309770dae3eb803abe1f23f97a6b8eb3c8
Signed-off-by: Son Nguyen <son.nguyen@catalyst.net.nz>
Merge "Destroy user's sessions when (Bug 1328705)"