chore(deps): allow psr/http-message v2 (#193)

Author: simPod

composer.json

@@ -32,7 +32,7 @@
         "php-http/client-common": "^2.0",
         "psr/http-client": "^1.0",
         "psr/http-factory": "^1.0",
-        "psr/http-message": "^1.0",
+        "psr/http-message": "^1.0 || ^2.0",
         "psr/log": "^1 || ^2 || ^3",
         "thecodingmachine/safe": "^1.0 || ^2.0"
     },