Merge pull request #16 from lanthaler/patch-1

Update php-http/message dependency to ^1.0

Author: sagikazarmark

composer.json

@@ -19,7 +19,7 @@
         "phpunit/phpunit": "^4.5",
         "php-http/httplug": "^1.0",
         "php-http/discovery": "~0.7",
-        "php-http/message": "~0.2.1",
+        "php-http/message": "^1.0",
         "guzzlehttp/psr7": "^1.0",
         "th3n3rd/cartesian-product": "^0.3"
     },