Update hibernate to latest version

[yvespp]

I tried to updated hibernate but tests started to fail. Once we have updated hibernate we can also update the java ee API versions.
Ref: #563

With 5.4.20.Final multiple tests fail with this error:

[ERROR] ch.puzzle.itc.mobiliar.test.PersistingEntityBuilderTest.testAmw  Time elapsed: 0.846 s  <<< ERROR!
javax.persistence.PersistenceException:
org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions. Collection : [ch.puzzle.itc.mobiliar.business.resourcegroup.entity.ResourceEntity.consumedMasterRelations#1]
Collection contents: [[]]
        at ch.puzzle.itc.mobiliar.test.PersistingEntityBuilderTest.testAmw(PersistingEntityBuilderTest.java:80)
Caused by: org.hibernate.HibernateException:
Illegal attempt to associate a collection with two open sessions. Collection : [ch.puzzle.itc.mobiliar.business.resourcegroup.entity.ResourceEntity.consumedMasterRelations#1]
Collection contents: [[]]
        at ch.puzzle.itc.mobiliar.test.PersistingEntityBuilderTest.testAmw(PersistingEntityBuilderTest.java:80)

With 5.3.18.Final all persistence tests fail with:

Cannot mock/spy class org.hibernate.internal.SessionImpl
Mockito cannot mock/spy because :
 - final class
        at ch.puzzle.itc.mobiliar.business.template.control.TemplatesScreenDomainServicePersistenceTest.before(TemplatesScreenDomainServicePersistenceTest.java:56)

Maybe it has to do with how we initialize the persistence context during tests?

[yvespp]

Same with 5.5.3.Final
The session can be printed with System.out.println(entityManager);
I noticed that it changes when MockitoAnnotations.openMocks(this) is called.
The error can be provoked by calling transaction.commit() after entityManager.persist(entity). Some commits work others don't.