tests: Separate tests from linter

.github/workflows/tox.yml

@@ -23,4 +23,24 @@ jobs:
         python -m pip install --upgrade pip
         pip install tox tox-gh-actions
     - name: Test with tox
-      run: tox
+      run: tox -e py37-pytest
+
+  lint:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.7]
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install apt dependencies
+      run: sudo apt install ldap-utils slapd libsasl2-dev libldap2-dev libssl-dev
+    - name: Install tox
+      run: |
+        python -m pip install --upgrade pip
+        pip install tox tox-gh-actions
+    - name: Linter
+      run: tox -e py37-lint