https://trello.com/c/INlaa5Yc/858-als-een-account-is-aangemaakt-in-communibase-beheer-die-geen-toegang-heeft-tot-deze-administratie-kan-hij-daar-toch-op-inloggen

made sure that sessions are removed from local memory as well, when calling MongoStore.destroy
Merge pull request #1 from DavidRip/master

Session destroy does not clear memory