improved DocumentManagerTest::testFindTranslationAndUpdate

see https://github.com/doctrine/phpcr-odm/issues/564

now we need to find a fix ..
@ElectricMaxxx does this make sense semantically? the bind translation event is triggered on flush, except if there was an explicit bind operation before.

if i understand correctly, doBindTranslation does not care whether the translation actually changed or not for the event to be raised. would it make more sense to only raise the event if there are actual changes - but then always raise it? an event listener might care about changes to the translation.