Add Github Action to run the test against multiple version of PHP

.github/workflows/ci.yaml

@@ -0,0 +1,40 @@
+name: CI
+
+on:
+    push:
+        branches: [master]
+    pull_request:
+        branches: [master]
+
+jobs:
+
+    phpunit:
+        name: PHPUnit
+        runs-on: ubuntu-latest
+
+        strategy:
+            fail-fast: false
+            matrix:
+                php-version:
+                    - "7.4"
+                    - "8.0"
+                    - "8.1"
+                    - "8.2"
+
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v3
+
+            - name: Setup PHP
+              uses: shivammathur/setup-php@v2
+              with:
+                  php-version: ${{ matrix.php-version }}
+                  coverage: none
+
+            - name: Install composer dependencies
+              uses: ramsey/composer-install@v2
+              with:
+                  dependency-versions: ${{ matrix.dependency-versions }}
+
+            - name: Run PHPUnit
+              run: vendor/bin/phpunit tests