adding readTypedRelationshipsOfNode(node, types)

Feel free to rename if you want. After running the tests a second time, the readRelationshipTypes test fails. But this is kind of a flaw with that one test, as any unclean db will fail (unless you only have types of `RELATED_TO`)--should pass CI with clean db, although it depends on running the readTypedRelationshipsOfNode after the readRelationshipTypes test.