Added support to Symfony 5

Author: gnugat

composer.json

@@ -12,12 +12,12 @@
     ],
     "require": {
         "php": ">=5.3.3",
-        "symfony/yaml": "^2.3 || ^3.0 || ^4.0"
+        "symfony/yaml": "^2.3 || ^3.0 || ^4.0 || ^5.0"
     },
     "require-dev": {
         "composer/composer": "^1.0@dev",
-        "symfony/filesystem": "^2.3 || ^3 || ^4",
-        "symfony/phpunit-bridge": "^4.0"
+        "symfony/filesystem": "^2.3 || ^3 || ^4 || ^5",
+        "symfony/phpunit-bridge": "^4.0 || ^5.0"
     },
     "autoload": {
         "psr-4": { "Incenteev\\ParameterHandler\\": "" }