Support PHP 7.1 and 8.0

Author: GrahamCampbell

Diff for: .github/workflows/test.yml

@@ -0,0 +1,50 @@
+name: Tests
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  tests:
+    name: PHP ${{ matrix.php }}
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        php: ['7.1', '7.2', '7.3', '7.4', '8.0']
+
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v2
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          extensions: curl
+          tools: composer:v2
+          coverage: none
+
+      - name: Setup Problem Matchers
+        run: echo "::add-matcher::${{ runner.tool_cache }}/phpunit.json"
+
+      - name: Install PHP 7 Dependencies
+        uses: nick-invision/retry@v1
+        with:
+          timeout_minutes: 5
+          max_attempts: 5
+          command: composer update --no-interaction --no-progress
+        if: "matrix.php != '8.0'"
+
+      - name: Install PHP 8 Dependencies
+        uses: nick-invision/retry@v1
+        with:
+          timeout_minutes: 5
+          max_attempts: 5
+          command: |
+            composer require "phpunit/phpunit:^9.3" --no-update
+            composer update --no-interaction --no-progress --ignore-platform-req=php
+        if: "matrix.php == '8.0'"
+
+      - name: Execute PHPUnit
+        run: vendor/bin/phpunit

Diff for: composer.json

@@ -17,10 +17,10 @@
         }
     ],
     "require": {
-        "php" : "^7.2"
+        "php" : "^7.1 || ^8.0"
     },
     "require-dev": {
-        "phpunit/phpunit" : "^8.5 || ^9.3"
+        "phpunit/phpunit" : "^7.5.15 || ^8.5 || ^9.3"
     },
     "autoload": {
         "psr-4": {
@@ -38,6 +38,9 @@
         }
     },
     "config": {
+        "preferred-install": "dist",
         "sort-packages": true
-    }
+    },
+    "minimum-stability": "dev",
+    "prefer-stable": true
 }

Diff for: phpunit.xml.dist

@@ -9,7 +9,7 @@
 >
     <testsuites>
         <testsuite name="AllTests">
-            <directory>tests</directory>
+            <directory>tests/</directory>
         </testsuite>
     </testsuites>
     <filter>