Tweak action

.github/workflows/python-package-poetry.yml

@@ -23,10 +23,13 @@ jobs:
       uses: actions/setup-python@v2
       with:
         python-version: ${{ matrix.python-version }}
-    - name: Install dependencies
+    - name: Install tooling
       run: |
+        python -m ensurepip
         python -m pip install --upgrade pip
-        python -m pip install flake8 pytest
+        python -m pip install flake8 poetry
+    -- name: Install dependencies
+      run: |
         poetry install
     - name: Lint with flake8
       run: |