5.1.0
NB: includes breaking changes to the existing discrimination tree implementation, despite only being a minor version bump. Should have done this in v5, but was impatient - and don't want to bump to version 6 so soon. The nature of the package and relatively low download count suggests that absolutely no-one will care, but if anyone does, feel free to reach out and I'll take care to not do this again.
- Added an async discrimination tree implementation - to facilitate secondary storage.
- Some breaking refactoring to the existing synchronous discrimination tree.