Merge pull request #304 from arduino/dependabot/pip/black-21.12b0

Bump black from 21.11b1 to 21.12b0

Author: per1234

poetry.lock

@@ -21,7 +21,7 @@ mkdocs = "^1.2.3"
 mkdocs-material = "^8.0.3"
 
 [tool.poetry.dev-dependencies]
-black = "^21.11b1"
+black = "^21.12b0"
 codespell = "^2.1.0"
 flake8 = "^4.0.1"
 pep8-naming = "^0.12.1"