Neo4j chokes on null values for properties

[erickpeirson]

If a node or edge property has value None, the JSONEncoder will serialize that value as null without complaining. Neo4j chokes on the null value, and returns a 500 server error, derailing the batch ingest. Two potential solutions come to mind:

• Check for and exclude properties with value None in get_node and get_relationship.
• Change None values to an empty string ("") or some (optional) default value.