Allow psr/http-message v2.0

Author: Jonathon Hill

composer.json

@@ -26,10 +26,10 @@
         }
     ],
     "require": {
-        "php": ">=5.3.0",
+        "php": "^8.0",
         "evenement/evenement": "^3.0 || ^2.0 || ^1.0",
         "fig/http-message-util": "^1.1",
-        "psr/http-message": "^1.0",
+        "psr/http-message": "^1.0 || ^2.0",
         "react/event-loop": "^1.2",
         "react/promise": "^3.2 || ^2.3 || ^1.2.1",
         "react/socket": "^1.16",