* Update requirements
* Update CI for p3.10
* Update numpy requirement
* Drop 🐍p3.6 support
Numpy also dropped support for p3.6
* Bind cython v0.29.28
* Bind pyworld to v0.2.10
> 0.2.10 is not p3.10.x compatible
* Update Dockerfile
* Fix the bug in split_dataset
* Make eval_split_size configurable
* Change test_loader to use load_tts_samples function
* Change eval_split_portion to eval_split_size and permits to set the absolute number of samples in eval
* Fix samplers unit test
* Add data unit test on GitHub workflow