add github/workflows

.github/workflows/run-tests.yml

@@ -0,0 +1,44 @@
+name: tests
+
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '0 0 * * *'
+
+jobs:
+    php-tests:
+        runs-on: ${{ matrix.os }}
+
+        strategy:
+            matrix:
+                php: [7.4, 7.3]
+                laravel: [7.*, 6.*]
+                dependency-version: [prefer-lowest, prefer-stable]
+                os: [ubuntu-latest]
+                include:
+                    - laravel: 7.*
+                      testbench: 5.*
+                    - laravel: 6.*
+                      testbench: 4.*
+
+        name: P${{ matrix.php }} - L${{ matrix.laravel }} - ${{ matrix.dependency-version }}
+
+        steps:
+            -   name: Checkout code
+                uses: actions/checkout@v1
+
+            -   name: Setup PHP
+                uses: shivammathur/setup-php@v2
+                with:
+                    php-version: ${{ matrix.php }}
+                    extensions: dom, curl, libxml, mbstring, zip, pcntl, pdo, sqlite, pdo_sqlite, bcmath, soap, intl, gd, exif, iconv, imagick
+                    coverage: none
+
+            -   name: Install dependencies
+                run: |
+                    composer require "laravel/framework:${{ matrix.laravel }}" "orchestra/testbench:${{ matrix.testbench }}" --no-interaction --no-update
+                    composer update --${{ matrix.dependency-version }} --prefer-dist --no-interaction --no-suggest
+
+            -   name: Execute tests
+                run: vendor/bin/phpunit