update guzzle adapter

Author: dbu

composer.json

@@ -21,7 +21,7 @@
     },
     "require-dev": {
         "phpunit/phpunit": "^4.4",
-        "php-http/guzzle6-adapter": "^0.3.1",
+        "php-http/guzzle6-adapter": "^0.4.1",
         "php-http/message": "^0.2.1",
         "symfony/symfony": "^2.7|^3.0",
         "polishsymfonycommunity/symfony-mocker-container": "~1.0",