run black --check

Author: Dominik Neise

.circleci/config.yml

@@ -3,12 +3,13 @@ version: 2.0
 my-steps: &steps
   - checkout
   - run: sudo pip install -r requirements.txt
-  - run: sudo pip install flake8 pytest
+  - run: sudo pip install flake8 pytest black
   - run: python --version ; pip --version ; pwd ; ls -l
   # stop the build if there are Python syntax errors or undefined names
   - run: flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics
   # exit-zero treats all errors as warnings.  The GitHub editor is 127 chars wide
   - run: flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+  - run: black . --check
   #- run: pytest # test_s2gs test_replays
   - run: python -m unittest discover test_s2gs
   - run: python -m unittest discover test_replays