allow php 8 & httplug 2

Author: martinlutter

composer.json

@@ -9,10 +9,10 @@
         }
     },
     "require": {
-        "php": "^7.1",
+        "php": "^7.1|^8.0",
         "psr/http-message": "^1.0",
         "php-http/client-implementation": "^1.0",
-        "php-http/httplug": "^1.0",
+        "php-http/httplug": "^1.0|^2.0",
         "php-http/message-factory": "^1.0",
         "php-http/discovery": "^1.0",
         "ext-json": "*"