Update to use Boltx

[andyleclair]

Hello! Wondering if you're interested in accepting pull requests. I have cause to use Neo4J and I'd love to use the Seraph DSL, however, bolt_sips is unmaintained, and this lib has some incompatibilities with... more recent libraries.

I've put some work in here to update Seraph to use Boltx, which does appear to be actively maintained. I've still got a few test failures to work through, but I figured before I dug in I'd see if this was something you all would be interested in first!