Move from TravisCI to Github Actions.

.github/workflows/tests.yml

@@ -0,0 +1,39 @@
+name: tests
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: true
+      matrix:
+        php: [ '7.0','7.1','7.2','7.3', '7.4' ]
+        stability: [ prefer-lowest, prefer-stable ]
+
+    name: PHP ${{ matrix.php }} - ${{ matrix.stability }}
+
+    steps:
+      - name: Checkout the code
+        uses: actions/checkout@v2
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          coverage: none
+          extensions: curl
+          php-version: ${{ matrix.php }}
+          tools: composer:v2
+
+      - name: Install composer dependencies
+        uses: nick-invision/retry@v2
+        with:
+          command: composer update --${{ matrix.stability }} --prefer-dist --no-interaction --no-progress
+          max_attempts: 5
+          timeout_minutes: 5
+
+      - name: Run the tests
+        run: vendor/bin/phpunit --verbose

composer.json

@@ -15,7 +15,7 @@
         "ext-curl": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7.5"
+        "phpunit/phpunit": "^6.0|^7.5"
     },
     "autoload": {
         "psr-4": {