Update Neo4j Driver to version 2.x

[phreed]

While it is not formally released 2.x has started showing up in the maven repositories.

• https://mvnrepository.com/artifact/org.neo4j.driver/neo4j-java-driver/2.0.0-alpha01
• https://github.com/neo4j/neo4j-java-driver/tree/2.0

[rjbaucells]

Once it is released we can update this project to use the new version