set exact version of black

gonchik · gonchik · commit 27a66eaf1deb · 2022-02-05T11:09:55.000+02:00
diff --git a/requirements-dev.txt b/requirements-dev.txt
@@ -4,7 +4,7 @@ pytest
 pytest-cov
 flake8
 flake8-no-fstring
-black
+black==21.12b0
 tox
 coverage
 codecov
