added php-http/message as dependency

Author: avigoldman

composer.json

@@ -16,7 +16,6 @@
   },
   "require": {
     "php": "^5.5 || ^7.0",
-    "psr/http-message": "^1.0",
     "php-http/httplug": "^1.0",
     "php-http/message": "^1.0", 
     "php-http/client-implementation": "^1.0",