style fix

.github/workflows/tox.yml

@@ -0,0 +1,20 @@
+name: TOX CI
+
+on:
+    push:
+        branches: [master]
+    pull_request:
+        branches: [master]
+
+jobs:
+    build:
+        runs-on: ubuntu-latest
+
+        steps:
+          - uses: actions/checkout@v2
+
+          - name: Building testenv ...
+            run: make testenv
+
+          - name: Running tests ...
+            run: make tox CMD="tox -c testenv/tox.ini"