add tox environment for formatting code with black

tomato42 · tomato42 · commit 77cabc01acc0 · 2021-05-21T00:11:06.000+02:00
diff --git a/tox.ini b/tox.ini
@@ -96,6 +96,13 @@ commands =
          flake8 setup.py speed.py src
          black --check --line-length 79 .
 
+[testenv:codeformat]
+basepython = python3
+deps =
+     black==19.10b0
+commands =
+         black --line-length 79 .
+
 [flake8]
 exclude = src/ecdsa/test*.py
 # We're just getting started. For now, ignore the following problems:
