bugfix for getConferenceSessions and mock method
bugfix for getConferenceSessions and mock method

olala7846/GAE-conferece-central,olala7846/udacity_fullstack_p4,olala7846/GAE-conferece-central,olala7846/udacity_fullstack_p4,olala7846/udacity_fullstack_p4,olala7846/GAE-conferece-central