Separate websocket internals for RPC (#1893)

* websocket centralization

* more centralization

* whoops

* Update WebSocket.js

src/index.js

@@ -57,4 +57,6 @@ module.exports = {
   User: require('./structures/User'),
   VoiceChannel: require('./structures/VoiceChannel'),
   Webhook: require('./structures/Webhook'),
+
+  WebSocket: require('./WebSocket'),
 };