Python v0.9.0.rc1

Fixed

• [#362]: Fix training deadlock with Python components.
• [#363]: Fix a crash when calling .train with some non-existent files
• [#355]: Remove a lot of possible crashes
• [#389]: Improve truncation (crash and consistency)

Added

• [#379]: Add the ability to call encode/encode_batch with numpy arrays
• [#292]: Support for the Unigram algorithm
• [#378], [#394], [#416], [#417]: Many new Normalizer and PreTokenizer
• [#403]: Add TemplateProcessing PostProcessor.
• [#420]: Ability to fuse the "unk" token in BPE.

Changed

• [#360]: Lots of improvements related to words/alignment tracking
• [#426]: Improvements on error messages thanks to PyO3 0.12