ci: py3.9, pypy3, some more pip metadata

Author: bollwyvl

.github/workflows/tests.yml

@@ -12,16 +12,19 @@ on:
 jobs:
   linux:
     name: ${{ matrix.PLATFORM }} py${{ matrix.PYTHON_VERSION }}
-    runs-on: ${{ matrix.PLATFORM }}
+    runs-on: ${{ matrix.PLATFORM }}-latest
     env:
       CI: True
       PYTHON_VERSION: ${{ matrix.PYTHON_VERSION }}
       CODECOV_TOKEN: e025254a-fe54-4914-8890-0c26e7aa0d07
     strategy:
       fail-fast: false
       matrix:
-        PYTHON_VERSION: ['3.6', '3.8']
-        PLATFORM: ['ubuntu-latest', 'macos-latest',  'windows-latest']
+        PYTHON_VERSION: ['3.6', '3.9', 'pypy3']
+        PLATFORM: ['ubuntu', 'macos',  'windows']
+        exclude:
+        - PLATFORM: windows
+          PYTHON_VERSION: pypy3
     steps:
       - name: Checkout
         uses: actions/checkout@v1
@@ -38,11 +41,13 @@ jobs:
       - name: Install python dependencies
         run: |
           pip install setuptools pip --upgrade --user
+      - name: Install project dependencies
           pip install -v -e ".[test]"
       - name: Show python environment
         run: |
           python --version
-          python -m pip list
+          python -m pip freeze
+          python -m pip check
       - name: Run python tests
         # See `setup.cfg` for full test options
         run: |