Add Spring Boot auto-configuration for Neo4j vector store

Comment From: King-Chau

@tzolov #114 Please review, thank you.

Comment From: tzolov

LGTM, thank you @King-Chau

Comment From: tzolov

Rebased, squashed and merged at: b625ab1c1589dc6be0240b2d76d7023d43a71dcd