Test against `ronin-db-activerecord` 0.3.0

[ronin-db-activerecord 0.3.0](https://github.com/ronin-rb/ronin-db-activerecord/tree/0.3.0) contains some breaking changes to the `WebVuln` model, so we should test `Ronin::Vulns::Importer` against the new version.