*improvements on Feedback
Merge remote-tracking branch 'gooru/master'

Conflicts:
	api/src/main/java/org/ednovo/gooru/domain/service/FeedbackServiceImpl.java
	api/src/main/java/org/ednovo/gooru/infrastructure/persistence/hibernate/FeedbackRepositoryHibernate.java
*Fixed [IClass & Assignment]  show proper error message
*Implemented Error validation CORE-1323 [Rating , Reactions & Tagging] Show proper validation error message
*naming convention on logger
Merge pull request #407 from cyrilraja/master

*improvements on Feedback
Merge remote-tracking branch 'goorus/master'
Removed unused codes and added code improvements