fix: add listeners to custom socket functions on the `created` hook instead of `beforeCreate` hook in the mixin lifecycle

src/Main.js

@@ -12,7 +12,7 @@ export default {
         Vue.prototype.$socket = observer.Socket;
 
         Vue.mixin({
-            beforeCreate(){
+            created(){
                 let sockets = this.$options['sockets']
 
                 this.$options.sockets = new Proxy({}, {