Introduce Github Actions

.github/workflows/ci.yml

@@ -0,0 +1,34 @@
+name: CI
+
+on: 
+  - push
+  - pull_request
+jobs:
+  ci:
+    name: CI checks
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        php:
+          - 5.6
+          - 7.0
+          - 7.1
+          - 7.2
+          - 7.3
+          - 7.4
+          - 8.0
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          tools: composer:v2
+      - name: Run composer install
+        run: composer install
+        env:
+          COMPOSER_ROOT_VERSION: dev-master
+      - run: vendor/bin/parallel-lint src
+      - run: composer cs-check
+      - run: composer test

composer.json

@@ -14,7 +14,8 @@
     "phpunit/phpunit": "^5.0 || ^6.0 || ^7.0 || ^8.0 || ^9.0",
     "ext-xdebug": "*",
     "php": "~5.6 || ~7.0",
-    "squizlabs/php_codesniffer": "^3.3"
+    "squizlabs/php_codesniffer": "^3.3",
+    "php-parallel-lint/php-parallel-lint": "^1.3"
   },
   "autoload-dev": {
     "psr-4": {