EPIC FAIL
My BUG in offering presentation, delete @Transactional while refactor groupService
	modified:   school-service/src/main/java/school/service/implementation/GroupServiceImpl.java
Unworked tests commented
	modified:   school-service/src/test/java/school/service/implementation/ConversationServiceImplTest.java
	modified:   school-service/src/test/java/school/service/implementation/CourseServiceImplTest.java
	modified:   school-service/src/test/java/school/service/implementation/MessageServiceImplTest.java