adds encrypted notification token for slack, fixes #77
adds encrypted notification token for slack, fixes #77

jayendra03/OpenTok-PHP-SDK,jayendra03/OpenTok-PHP-SDK,aoberoi/Opentok-PHP-SDK,aoberoi/Opentok-PHP-SDK,jayendra03/OpenTok-PHP-SDK,opentok/OpenTok-PHP-SDK,aoberoi/Opentok-PHP-SDK,jayendra03/OpenTok-PHP-SDK