Feature/GitHub actions (#1)

Add github actions support

.github/workflows/static.yml

@@ -0,0 +1,43 @@
+name: Static Analysis
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  composer-validate:
+    name: Composer Validate
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Validate dependencies
+        uses: php-actions/composer@v5
+        with:
+          command: validate --strict
+
+  phpstan:
+    name: PHPStan
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 7.4
+          tools: composer:v2
+          coverage: none
+
+      - name: Install Dependencies
+        uses: nick-invision/retry@v1
+        with:
+          timeout_minutes: 5
+          max_attempts: 5
+          command: composer install --no-interaction --no-progress
+
+      - name: Execute PHPStan
+        run: vendor/bin/phpstan analyze --no-progress src/

.github/workflows/tests.yml

@@ -0,0 +1,15 @@
+name: Tests
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  build-test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: php-actions/composer@v5
+      - uses: php-actions/phpunit@v2
+

composer.json

@@ -11,7 +11,7 @@
     }
   ],
   "require": {
-    "php": "^7.1 || 8.0",
+    "php": "^7.1 || ^8.0",
     "php-http/client-common": "^2.0",
     "php-http/discovery": "^1.6",
     "php-http/httplug": "^2.0",