CI workflow: misc. fixes

.github/workflows/ci.yml

@@ -37,17 +37,35 @@ jobs:
     - name: Lint with flake8
       run: |
         pip install flake8
-        flake8 src scripts conftest.py
+        flake8 src scripts setup.py
 
   pytest:
 
     needs: lint
+
+    strategy:
+      matrix:
+        include:
+            - os: ubuntu-18.04
+              python-version: 3.5
+              toxenv: py35
+            - os: ubuntu-18.04
+              python-version: 3.6
+              toxenv: py36
+            - os: ubuntu-20.04
+              python-version: 3.7
+              toxenv: py37
+            - os: ubuntu-20.04
+              python-version: 3.8
+              toxenv: py38
+            - os: ubuntu-20.04
+              python-version: 3.9
+              toxenv: py39
+
     env:
-      # Configure pkg-config to use OpenSSL from Homebrew
-      PKG_CONFIG_PATH: /usr/local/opt/openssl@1.1/lib/pkgconfig
       TOXENV: ${{ matrix.toxenv }}
 
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     timeout-minutes: 10
 
     steps:
@@ -55,14 +73,14 @@ jobs:
       with:
         # just fetching 1 commit is not enough for setuptools-scm, so we fetch all
         fetch-depth: 0
-    - name: Set up Python
+    - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v2
       with:
-        python-version: 3.5
+        python-version: ${{ matrix.python-version }}
     - name: Install Python requirements
       run: |
         python -m pip install --upgrade pip setuptools wheel
-        pip install -r requirements.d/development.txt
+        pip install -r requirements.d/dev.txt
     - name: run pytest via tox
       run: |
         tox --skip-missing-interpreters
@@ -72,5 +90,4 @@ jobs:
         OS: ${{ runner.os }}
         python: ${{ matrix.python-version }}
       with:
-        token: ${{ secrets.CODECOV_TOKEN }}
         env_vars: OS, python