tests: Try to fix tox-gh-action?

.github/workflows/tox.yml

@@ -17,9 +17,10 @@ jobs:
       uses: actions/setup-python@v2
       with:
         python-version: ${{ matrix.python-version }}
-    - name: Install dependencies
+    - name: Install apt dependencies
+      run: sudo apt install ldap-utils slapd
+    - name: Install tox
       run: |
-        sudo apt install ldap-utils slapd
         python -m pip install --upgrade pip
         pip install tox tox-gh-actions
     - name: Test with tox

tox.ini

@@ -17,6 +17,11 @@ commands =
     py37-pytest: pytest {posargs} -c pytest.ini
     py37-lint: flake8 moulinette test
 
+[gh-actions]
+python =
+  3.7: py37
+  3.9: py39
+
 [testenv:format]
 basepython = python3
 commands = black {posargs} moulinette test