Add github actions to run tests

.github/workflows/php.yml

@@ -0,0 +1,40 @@
+name: PHP Tests
+
+on: [ push, pull_request ]
+
+jobs:
+
+  build:
+    strategy:
+      matrix:
+        operating-system: [ ubuntu-latest ]
+        php-versions: [ '7.3', '7.4', '8.0', '8.1' ]
+        experimental: [ false ]
+        include:
+          - php-versions: '8.2'
+            operating-system: ubuntu-latest
+            experimental: true
+      fail-fast: false
+    runs-on: ${{ matrix.operating-system }}
+    continue-on-error: ${{ matrix.experimental }}
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-versions }}
+
+      - name: Validate composer.json and composer.lock
+        run: composer validate
+
+      - name: Install dependencies
+        if: "${{ matrix.experimental == false }}"
+        run: composer install --prefer-dist --no-progress --no-suggest
+
+      - name: Install dependencies, ignore php requirements
+        if: "${{ matrix.experimental == true }}"
+        run: composer install --prefer-dist --no-progress --no-suggest --ignore-platform-reqs
+
+      - name: Run test suite
+        run: composer run-script test

.gitignore

@@ -2,3 +2,8 @@
 .tmp
 pkg
 tmp
+
+.phpunit.result.cache
+composer.lock
+.idea/
+vendor/

composer.json

@@ -13,16 +13,23 @@
     }
   ],
   "require": {
-    "php": "^5.6 || ^7.0 || ^8.0",
+    "php": "^7.3 || ^8.0",
     "phpseclib/phpseclib": "^2.0.31"
   },
   "require-dev": {
+    "roave/security-advisories": "dev-latest",
     "phpunit/phpunit": "^9.0"
   },
   "suggest": {
-    "ext-mcrypt": "required if you use encryption cast5"
+    "ext-mcrypt": "required if you use encryption cast5",
+    "ext-sodium": "required if you use signature ed25519"
   },
   "autoload": {
-    "classmap": ["lib/"]
+    "classmap": [
+      "lib/"
+    ]
+  },
+  "scripts": {
+    "test": "./vendor/bin/phpunit"
   }
 }