ci: update actions to ubuntu-latest

And other refinements to bring actions up to date.

Signed-off-by: Daniel Bluhm <dbluhm@pm.me>

.github/workflows/checks.yml

@@ -0,0 +1,58 @@
+name: Checks
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  format:
+    name: Formatting (with black)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.9
+      - name: Cache python environment
+        id: cache-env
+        uses: actions/cache@v3
+        with:
+          path: ${{ env.pythonLocation }}
+          key: ${{ runner.os }}-formatting-black-22.3.0
+      - name: Install black
+        if: steps.cache-env.outputs.cache-hit != 'true'
+        run: |
+          pip install black==23.3.0
+      - name: Black Format Check
+        run: |
+          black --check pydid
+
+  test:
+    name: Tests
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install poetry
+        run: pipx install poetry
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: poetry
+      - name: Install dependencies
+        run: poetry install
+      - name: Lint with flake8
+        run: |
+          # stop the build if there are Python syntax errors or undefined names
+          poetry run flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+          # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+          poetry run flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+      - name: Run pytest
+        run: poetry run pytest