removed all manual assosiations, added cascade

...t2016/v233/SmartMat/controller/group/GroupController.java

...ava/ntnu/idatt2016/v233/SmartMat/entity/group/Fridge.java

...java/ntnu/idatt2016/v233/SmartMat/entity/group/Group.java

...u/idatt2016/v233/SmartMat/entity/group/UserGroupAsso.java

.../ntnu/idatt2016/v233/SmartMat/entity/product/Product.java

...n/java/ntnu/idatt2016/v233/SmartMat/entity/user/User.java

...u/idatt2016/v233/SmartMat/service/group/GroupService.java

...016/v233/SmartMat/service/group/UserGroupAssoService.java

...6/v233/SmartMat/repository/group/GroupRepositoryTest.java

...v233/SmartMat/service/group/UserGroupAssoServiceTest.java