CAS-1389: Logout fails as an error happens when tickets are marked as expired

First commit
CAS-1389: Logout fails as an error happens when tickets are marked as expired

change debug message and add a test to confirm the correct behaviour
CAS-1389: Logout fails as an error happens when tickets are marked as expired

Updates after Misagh's code review
Merge pull request #365 from leleuj/CAS-1389

CAS-1389: Logout fails as an error happens when tickets are marked as expired