Changes:
* Update Python packaging ([124](https://github.com/xcsf-dev/xcsf/pull/124))
* Add Python `validation_data` input check ([136](https://github.com/xcsf-dev/xcsf/pull/136))
* Fix sanitizer, free test memory, fix neural saving ([146](https://github.com/xcsf-dev/xcsf/pull/146))
* Update cJSON and pybind11 libs ([147](https://github.com/xcsf-dev/xcsf/pull/147))