Updated middleware to 4.0

Author: WyriHaximus

composer.json

@@ -13,8 +13,8 @@
     "php": "^7.0",
     "api-clients/client-services": "^1.1",
     "api-clients/foundation": "dev-master",
-    "api-clients/middleware-json": "^1.0",
-    "api-clients/middleware-user-agent": "^1.0",
+    "api-clients/middleware-json": "^2.0",
+    "api-clients/middleware-user-agent": "^2.0",
     "api-clients/resource": "^3.0"
   },
   "require-dev": {