feat: allow Symfony 6 installation

Author: jdecool

.github/workflows/ci.yml

@@ -18,8 +18,9 @@ jobs:
     runs-on: ubuntu-18.04
     strategy:
       matrix:
-        version: ['7.1', 7.2', '7.3', '7.4', '8.0']
+        version: ['7.1', '7.2', '7.3', '7.4', '8.0']
         flags: ['', '--prefer-lowest']
+      fail-fast: false
     steps:
       - uses: actions/checkout@master
       - uses: shivammathur/setup-php@v2

composer.json

@@ -9,18 +9,18 @@
     "prefer-stable": true,
     "require": {
         "php": ">=7.1.3",
-        "symfony/config": "^4.4|^5.0",
-        "symfony/yaml": "^4.4|^5.0",
-        "symfony/routing": "^4.4|^5.0",
-        "symfony/expression-language": "^4.4|^5.0",
-        "symfony/security-core": "^4.4|^5.0"
+        "symfony/config": "^4.4|^5.0|^6.0",
+        "symfony/yaml": "^4.4|^5.0|^6.0",
+        "symfony/routing": "^4.4|^5.0|^6.0",
+        "symfony/expression-language": "^4.4|^5.0|^6.0",
+        "symfony/security-core": "^4.4|^5.0|^6.0"
     },
     "require-dev": {
         "atoum/atoum": "^3.4|^4.0",
         "friendsofphp/php-cs-fixer": "^2.19",
         "m6web/symfony2-coding-standard": "~1.2",
         "m6web/php-cs-fixer-config": "^1.0",
-        "symfony/http-foundation": "^4.4|^5.0"
+        "symfony/http-foundation": "^4.4|^5.0|^6.0"
     },
     "extra": {
         "branch-alias": {