Replace TravisCI with GitHub Actions

.github/workflows/phpunit.yml

@@ -0,0 +1,70 @@
+name: PHPUnit
+
+on:
+  push:
+    branches-ignore:
+      - 'analysis-**'
+
+jobs:
+  phpunit:
+    name: PHP ${{ matrix.php }}
+    runs-on: ubuntu-latest
+
+    strategy:
+        fail-fast: false
+        matrix:
+            php:
+                - '7.2'
+                - '7.3'
+                - '7.4'
+                - '8.0'
+                - '8.1'
+            cmd: ['composer test']
+            coverage: [false]
+            include:
+                - php: '7.2'
+                  flags: '--prefer-stable --prefer-lowest'
+                  coverage: true
+                  cmd: 'composer test-ci'
+                - php: '7.2'
+                  flags: '--prefer-stable --prefer-lowest'
+
+    steps:
+        - name: Clone repository
+          uses: actions/checkout@v2.3.5
+
+        - name: Setup PHP ${{ matrix.php }}
+          uses: shivammathur/setup-php@2.15.0
+          with:
+            php-version: ${{ matrix.php }}
+            tools: composer:v2
+            coverage: pcov
+
+        - name: Validate composer.json and composer.lock
+          run: composer validate
+
+        - name: Get composer cache directory
+          id: composer-cache
+          run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+
+        - name: Cache composer packages
+          uses: actions/cache@v2.1.6
+          with:
+            path: ${{ steps.composer-cache.outputs.dir }}
+            key: ${{ runner.os }}-php-${{ matrix.php }}-${{ hashFiles('**/composer.lock') }}
+            restore-keys: ${{ runner.os }}-php-${{ matrix.php }}-
+
+        - name: Install dependencies
+          run: composer update ${{ matrix.flags }} --prefer-source --no-interaction --ignore-platform-reqs
+
+        - name: Run test suite
+          run: |
+            vendor/bin/http_test_server > /dev/null 2>&1 &
+            cd ./tests/server/ssl && ./generate.sh && pwd && ls -la && cd ../../../
+            ${{ matrix.cmd }}
+
+        - name: Upload coverage data
+          if: matrix.coverage == true
+          run: |
+            wget https://scrutinizer-ci.com/ocular.phar
+            php ocular.phar code-coverage:upload --format=php-clover build/coverage.xml