apply formatting with black (#1038)

* applying black (with the default 88-column limit)

* add flake8

* add isort

* fix isort

tests/test_normalizer.py

@@ -1,7 +1,10 @@
 import pytest
 
 from whisper.normalizers import EnglishTextNormalizer
-from whisper.normalizers.english import EnglishNumberNormalizer, EnglishSpellingNormalizer
+from whisper.normalizers.english import (
+    EnglishNumberNormalizer,
+    EnglishSpellingNormalizer,
+)
 
 
 @pytest.mark.parametrize("std", [EnglishNumberNormalizer(), EnglishTextNormalizer()])