Update TargetNode on RelationshipProperties

[gerrit.meier]

I think the same response is valid here that I just wrote in the other thread:

Handling Automatic Relationship Updates in Neo4j vs JPA

I updated the the example and added a intentional failing test there: If I got you correctly, you are only changing the target node but not the relationship properties instance, right? You would have to replace also the relationship properties with a new class. Otherwise, SDN would assume that this is still the same relationship, having the same target node.