use github actions to run composer

.github/workflows/composer.yml

@@ -0,0 +1,33 @@
+name: PHP Composer
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Validate composer.json and composer.lock
+        run: composer validate
+
+      - name: Cache Composer packages
+        id: composer-cache
+        uses: actions/cache@v2
+        with:
+          path: vendor
+          key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-php-
+
+      - name: Install dependencies
+        if: steps.composer-cache.outputs.cache-hit != 'true'
+        run: composer install --prefer-dist --no-progress --no-suggest
+      - name: Run test suite
+        run: composer run-script test

composer.json

@@ -33,5 +33,8 @@
         "phpunit/phpunit": "^9",
         "orchestra/testbench": "^4",
         "mockery/mockery": "^1.1"
+    },
+    "scripts": {
+        "test": "phpunit"
     }
 }