Using latest version of discovery

Author: Nyholm

composer.json

@@ -14,7 +14,7 @@
         "php": "^5.4|^7.0",
         "php-http/httplug": "^1.0",
         "kriswallsmith/buzz": "^0.15",
-        "php-http/discovery": "^0.8"
+        "php-http/discovery": "^0.9"
     },
     "require-dev": {
         "php-http/adapter-integration-tests": "^0.3",