Removed testing code from ConcreteConversation
Refactored ConcreteConversation per Michael's suggestion to create a
deliverParticipantMessage method to take care of the null check logic
Merge branch 'notifyParticipantsOfAttendance_ACE-46' of github.com:ualerts-org/ualerts-chat into notifyParticipantsOfAttendance_ACE-46

Conflicts:
	org.ualerts.chat.service/src/main/java/org/ualerts/chat/service/api/concrete/ConcreteConversation.java