ci: check black formatting

Author: davidhewitt

.github/workflows/ci.yml

@@ -6,6 +6,20 @@ on:
   pull_request:
 
 jobs:
+  fmt:
+    runs-on: "ubuntu-latest"
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: "3.x"
+
+      - run: pip install black
+
+      - run: black --check .
+
   build:
     name:  ${{ matrix.python-version }} ${{ matrix.platform.os }}-${{ matrix.platform.python-architecture }}
     runs-on: ${{ matrix.platform.os }}

pyproject.toml

@@ -4,3 +4,6 @@ build-backend = "setuptools.build_meta"
 
 [tool.setuptools_scm]
 write_to = "setuptools_rust/version.py"
+
+[tool.isort]
+profile = "black"