Run tests as GitHub Actions (julien-duponchelle#376)

To easier find out when changes break the tests.

- Use Python 3.7 for starters, because it's the oldest still-supported CPython
  interpreter version. More can be added in a subsequent step.
- Use "docker compose" to run the Percona versions from the dev readme. Different
  MySQL implementations (e.g. MariaDB, Oracle, etc.) could be added on top.
- The test suite is skipping `test_no_trailing_rotate_event` because it requires a
  different test setup, with access to the binlog files.
- The test suite also skips `test_end_log_pos` for now, because it currently
  fails and the best solution wasn't obvious to me, the original author should
  have a look.

.github/workflows/pytest.yml

@@ -0,0 +1,33 @@
+name: PyTest
+on: push
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    timeout-minutes: 2
+
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v2
+
+      - name: Setup Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: "3.7"
+
+      - name: Run database server in docker
+        run: |
+          docker compose create
+          docker compose start
+          # Wait for the services to accept connections,
+          # TODO: do that smarter, poll connection attempt until it succeeds
+          sleep 30
+
+      - name: Install dependencies
+        run: |
+          pip install .
+          pip install pytest
+
+      - name: Run test suite
+        run: |
+          pytest -k "not test_no_trailing_rotate_event and not test_end_log_pos"

docker-compose.yml

@@ -0,0 +1,17 @@
+version: '3.2'
+services:
+  percona-5.7:
+    image: percona:5.7
+    environment:
+      MYSQL_ALLOW_EMPTY_PASSWORD: true
+    ports:
+      - 3306:3306
+    command: mysqld --log-bin=mysql-bin.log --server-id 1 --binlog-format=row --gtid_mode=on --enforce-gtid-consistency=on --log_slave_updates
+
+  percona-5.7-ctl:
+    image: percona:5.7
+    environment:
+      MYSQL_ALLOW_EMPTY_PASSWORD: true
+    ports:
+      - 3307:3307
+    command: mysqld --log-bin=mysql-bin.log --server-id 1 --binlog-format=row --gtid_mode=on --enforce-gtid-consistency=on --log_slave_updates -P 3307