Add GitHub workflows tests

.github/workflows/main.yml

@@ -0,0 +1,25 @@
+name: Tests
+
+on: [push, pull_request, workflow_dispatch]
+
+jobs:
+  run-tests:
+    name: Run tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y pyqt5-dev-tools xvfb
+
+      - name: Setup Python
+        uses: actions/setup-python@v2
+
+      - name: Install tox
+        run: pip install tox
+
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Run tests
+        run: tox -- --forked --verbose