Change dependency for the message part (#2)

Author: Jean85

composer.json

@@ -5,7 +5,7 @@
     "require": {
         "sentry/sentry": "^2.0.1",
         "php-http/curl-client": "^1.0|^2.0",
-        "guzzlehttp/psr7": "^1.0"
+        "http-interop/http-factory-guzzle": "^1.0"
     },
     "license": "MIT",
     "authors": [