Create GitHub test action

.github/workflows/phpunit.yml

@@ -0,0 +1,26 @@
+name: PHPUnit
+
+on:
+  pull_request:
+  push:
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: PHPUnit
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php-version: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4']
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-version }}
+      - name: Composer install
+        run: composer install
+      - name: PHPUnit / PHP ${{ matrix.php-version }}
+        run: ./vendor/bin/phpunit