allow symfony 5

Author: Jeroeny

composer.json

@@ -9,14 +9,14 @@
         "php": "^7.1.3",
         "enqueue/enqueue": "^0.9",
         "queue-interop/queue-interop": "^0.7|^0.8",
-        "symfony/event-dispatcher": "^3.4|^4"
+        "symfony/event-dispatcher": "^3.4|^4|^5"
     },
     "require-dev": {
         "phpunit/phpunit": "~5.5",
-        "symfony/dependency-injection": "^3.4|^4",
-        "symfony/config": "^3.4|^4",
-        "symfony/http-kernel": "^3.4|^4",
-        "symfony/filesystem": "^3.4|^4",
+        "symfony/dependency-injection": "^3.4|^4|^5",
+        "symfony/config": "^3.4|^4|^5",
+        "symfony/http-kernel": "^3.4|^4|^5",
+        "symfony/filesystem": "^3.4|^4|^5",
         "enqueue/null": "0.9.x-dev",
         "enqueue/fs": "0.9.x-dev",
         "enqueue/test": "0.9.x-dev"
@@ -29,7 +29,7 @@
         "docs": "https://github.com/php-enqueue/enqueue-dev/blob/master/docs/index.md"
     },
     "suggest": {
-        "symfony/dependency-injection": "^2.8|^3|^4 If you'd like to use async event dispatcher container extension."
+        "symfony/dependency-injection": "^2.8|^3|^4|^5 If you'd like to use async event dispatcher container extension."
     },
     "autoload": {
         "psr-4": { "Enqueue\\AsyncEventDispatcher\\": "" },