Merge pull request #12 from FlorianVen/php8

Allow PHP 8

Author: dpdplugin

composer.json

@@ -25,11 +25,10 @@
     }
   },
   "require": {
-    "php": "^5.5 || ^7.0",
+    "php": "^5.5 || ^7.0 || ^8.0",
     "ext-json": "*"
   },
   "require-dev": {
-    "phpunit/phpunit": "~6.5.0",
     "symfony/yaml": "^4.2",
     "donatj/mock-webserver": "^2.0",
     "overtrue/phplint": "^1.1",