test: Switched to GitHub Actions workflow

Author: alexsoft

.github/workflows/tests.yml

@@ -0,0 +1,33 @@
+name: PHPUnit tests
+
+on:
+    - push
+    - pull_request
+
+jobs:
+    tests:
+        runs-on: ubuntu-latest
+        strategy:
+            fail-fast: true
+            matrix:
+                php: [7.2, 7.3, 7.4]
+                stability: [prefer-lowest, prefer-stable]
+
+        name: Tests on PHP ${{ matrix.php }} - ${{ matrix.stability }}
+
+        steps:
+            - name: Checkout code
+              uses: actions/checkout@v2
+
+            - name: Setup PHP
+              uses: shivammathur/setup-php@v2
+              with:
+                  php-version: ${{ matrix.php }}
+                  tools: composer:v2
+                  coverage: none
+
+            - name: Install dependencies
+              run: composer update --${{ matrix.stability }} --prefer-dist --no-interaction --no-progress
+
+            - name: Execute tests
+              run: vendor/bin/phpunit --verbose