title: neography / neo4j change relationship end point to another node
body: <p>i am using neography as wrapper of the REST api for Neo4j graph database.
  I often need to change the end node of a relationship, but i am not able to do this using neography.</p>
  
  <p>Of course, i can delete the relation then recreate it with the new end point node, but it's not optimized.</p>
  
  <p>Does anyone had this problem?</p>
  
  <p>Thanks.</p>