Adds a Neo4j service to release workflow

[alexthomas93]

This PR adds a Neo4j service to the _release.yml workflow and removes unneeded environment variables from the integration tests step.

[efriis]

you sure you want to remove the top-level namespace? that's what other packages do

if you're worried about import time, you could use a __getattr__ function instead that dynamically looks up objects and imports them when requested

[efriis]

otherwise lgtm!

[alexthomas93]

you sure you want to remove the top-level namespace? that's what other packages do

if you're worried about import time, you could use a __getattr__ function instead that dynamically looks up objects and imports them when requested

Yeah, I think I was prematurely trying to optimise the imports. I've reverted things to how they were for now on the imports side. Will merge