Add GitHub workflow ci

ci.yml

@@ -0,0 +1,33 @@
+name: CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        php: [7.x, 8.x]
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use PHP ${{ matrix.php }}
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          tools: composer:v2
+          coverage: none
+      - name: Setup problem matchers
+        run: echo "::add-matcher::${{ runner.tool_cache }}/phpunit.json"
+      - name: Install latest dependencies
+        uses: nick-invision/retry@v2
+        with:
+          timeout_minutes: 5
+          max_attempts: 5
+          command: composer update --no-interaction --no-progress
+      - run: vendor/bin/phpunit