* metrics: added bleu score and test bleu
* metrics: fixed type hints in bleu
* bleu score moved to metrics/functional/nlp.py
* refactor with torch.Tensor
* Update test_sequence.py
* refactor as Borda requests and nltk==3.2
* locked nltk==3.3
* nltk>=3.3, parametrized smooth argument for test
* fix bleu_score example
* added class BLEUScore metrics and test
* added class BLEUScore metrics and test
* update CHANGELOG
* refactor with torchtext
* torchtext changed to optional import
* fix E501 line too long
* add else: in optional import
* remove pragma: no-cover
* constants changed to CAPITALS
* remove class in tests
* List -> Sequence, conda -> pip, cast with tensor
* add torchtext in test.txt
* remove torchtext from test.txt
* bump torchtext to 0.5.0
* bump torchtext to 0.5.0
* Apply suggestions from code review
* ignore bleu score in doctest, renamed to nlp.py
* back to implementation with torch
* remove --ignore in CI test, proper reference format
* apply justus comment
Co-authored-by: Jirka Borovec <Borda@users.noreply.github.com>
Jeff Yang