Migrate to GitHub Actions for CI

Author: WyriHaximus

.github/workflows/ci.yml

@@ -0,0 +1,24 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  PHPUnit:
+    name: PHPUnit (PHP ${{ matrix.php }})
+    runs-on: ubuntu-20.04
+    strategy:
+      matrix:
+        php:
+          - 7.2
+          - 7.1
+          - 7.0
+    steps:
+      - uses: actions/checkout@v2
+      - uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          coverage: xdebug
+      - run: composer install
+      - run: vendor/bin/phpunit --coverage-text

.travis.yml

@@ -1,5 +1,7 @@
 # A PSR-15 middleware adapter for react/http
 
+[![CI status](https://github.com/friends-of-reactphp/http-middleware-psr15-adapter/workflows/CI/badge.svg)](https://github.com/friends-of-reactphp/http-middleware-psr15-adapter/actions)
+
 Wraps PSR-15 middleware into coroutines using [`RecoilPHP`](https://github.com/recoilphp) making them usable within `react/http` as middleware.
 
 # Install