Use emptyDir for Neo4j deployment plugin volumes instead of hostPath.
With this change we get rid of the dependency on hostPath and thus the
dependency on the hosts filesystem and pods permissions to the hostPath.
The custom Neo4j deployment can now also run on GKE (and other k8s
clusters).

I also sorted the config options for for Neo4j and disabled
auth. The disabling of Neo4j auth seems to be a consistent setting
through this repo (docker examples, and ECS examples).
Signed-off-by: Jonas Brunsgaard <jonas.brunsgaard@gmail.com>