Bump ratchet/rfc6455 to ^0.4 for api consistency

Author: andrewmy

composer.json

@@ -18,7 +18,8 @@
         "thruway/client": "^0.5.5",
         "thruway/pawl-transport": "^0.5.2",
         "voryx/thruway-common": "^1.0.1",
-        "ratchet/pawl": "^0.4.3"
+        "ratchet/pawl": "^0.4.3",
+        "ratchet/rfc6455": "^0.4.0"
     },
     "suggest": {
         "thruway/client": "Client for Thruway and the WAMP (Web Application Messaging Protocol).",