add support for symfony 6

Author: jrushlow

composer.json

@@ -6,15 +6,15 @@
     "minimum-stability": "dev",
     "require": {
         "php": ">=7.2.5",
-        "symfony/config": "^4.4 | ^5.0",
-        "symfony/dependency-injection": "^4.4 | ^5.0",
+        "symfony/config": "^4.4 | ^5.0 | ^6.0",
+        "symfony/dependency-injection": "^4.4 | ^5.0 | ^6.0",
         "symfony/deprecation-contracts": "^2.2",
-        "symfony/http-kernel": "^4.4 | ^5.0"
+        "symfony/http-kernel": "^4.4 | ^5.0 | ^6.0"
     },
     "require-dev": {
         "doctrine/orm": "^2.7",
         "friendsofphp/php-cs-fixer": "^3.0",
-        "symfony/framework-bundle": "^4.4 | ^5.0",
+        "symfony/framework-bundle": "^4.4 | ^5.0 | ^6.0",
         "symfony/phpunit-bridge": "^5.0",
         "vimeo/psalm": "^4.3",
         "doctrine/doctrine-bundle": "^2.0.3"