Marked several components as incompatible with EventDispatcher 5.

Author: derrabus

composer.json

@@ -23,7 +23,7 @@
     },
     "require-dev": {
         "symfony/config": "^3.4|^4.0|^5.0",
-        "symfony/event-dispatcher": "^4.3|^5.0",
+        "symfony/event-dispatcher": "^4.3",
         "symfony/dependency-injection": "^3.4|^4.0|^5.0",
         "symfony/lock": "^3.4|^4.0|^5.0",
         "symfony/process": "^3.4|^4.0|^5.0",
@@ -41,7 +41,7 @@
     },
     "conflict": {
         "symfony/dependency-injection": "<3.4",
-        "symfony/event-dispatcher": "<4.3",
+        "symfony/event-dispatcher": "<4.3|>=5",
         "symfony/process": "<3.3"
     },
     "autoload": {