allow php 8

Author: oscarotero

composer.json

@@ -24,14 +24,14 @@
         "issues": "https://github.com/oscarotero/Embed/issues"
     },
     "require": {
-        "php": "^5.6|^7.0",
+        "php": "^5.6|^7.0|^8.0",
         "ext-curl": "*",
         "ext-dom": "*",
         "ext-mbstring": "*",
         "composer/ca-bundle": "^1.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8|^5.7",
+        "phpunit/phpunit": "^5.7|^6.0|^7.0",
         "friendsofphp/php-cs-fixer": "^2.0"
     },
     "autoload": {