Update test suite

Author: sagikazarmark

composer.json

@@ -22,7 +22,7 @@
     },
     "require-dev": {
         "ext-curl": "*",
-        "php-http/adapter-integration-tests": "^0.3",
+        "php-http/adapter-integration-tests": "^0.4",
         "guzzlehttp/ringphp": "^1.1",
         "php-http/client-common": "^1.0",
         "guzzlehttp/psr7": "^1.2",