Replace Travis config with GH Actions

.github/workflows/test.yml

@@ -0,0 +1,32 @@
+name: phpunit
+
+on:
+  push:
+    branches:
+      - '**'
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        php-version: ['5.6', '7.4', '8.3']
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up PHP ${{ matrix.php-version }}
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-version }}
+
+      - name: Install dependencies
+        run: composer install
+
+      - name: Run tests
+        run: vendor/bin/phpunit QueryGeneratorTest.php