Unit tests require a running Neo4j instance

[glesica]

Right now the unit tests require a running server. Worse, they mutate the server, meaning we could accidentally screw with someone's local DB (which shouldn't matter, but might).

We should split the tests into two parts:

1. A unit test suite that doesn't require a running server
2. A functional test suite that does require a running server and (ideally) bootstraps an ephemeral server itself on a custom port, possibly using Docker

The unit tests can probably just use recorded payloads from an actual server to test response parsing. We can make assertions about the requests themselves as well.