Update workflows to use poetry to install deps

* Workflows upgraded to setup-python v4.
* Workflows now install deps using poetry.
* Lint and test run through poetry interface.
* Deps cached for faster testing in later runs.

.github/workflows/test-and-run.yml

@@ -19,20 +19,24 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v3
+    - name: Install poetry
+      uses: pipx install poetry
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v3
+      uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
+        cache: poetry
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install flake8 pytest
+        poetry env use "${{ matrix.python-version }}"
+        poetry install
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names
-        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+        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
-        flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+        poetry run flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
     - name: Test with pytest
       run: |
-        python -m pytest tests/
+        poetry run pytest tests/