No STDOUT messages

[danodonovan]

Could these lines be cut from neo4j/__init__.py?

metadata = getattr(unit_of_work, "metadata", None)
print(metadata) # TODO

The metadata print fills my console 👎 and isn't controllable with logging.

[danodonovan]

To cover #258

[danodonovan]

I'm afraid I can't see the TeamCity reasons for the failing tests - tests pass locally with tox. I'm happy to fix the PR if someone can share the errors!