Switch to stable php-http/message version.

Author: mekras

composer.json

@@ -20,8 +20,8 @@
     },
     "require-dev": {
         "guzzlehttp/psr7": "^1.0",
-        "php-http/adapter-integration-tests": "0.3",
-        "php-http/message": "^0.2",
+        "php-http/adapter-integration-tests": "dev-master#836cdff8294174cceeae54601ab4079c309227b7",
+        "php-http/message": "^1.0",
         "phpunit/phpunit": "^4.8",
         "zendframework/zend-diactoros": "^1.0"
     },