update models + added social network account services

lib/User/Validator/TimeZoneValidator.php

@@ -0,0 +1,20 @@
+<?php
+namespace Da\User\Validator;
+
+use Da\User\Contracts\ValidatorInterface;
+
+class TimeZoneValidator implements ValidatorInterface
+{
+    protected $timezone;
+
+    public function __construct($timezone)
+    {
+        $this->timezone = $timezone;
+    }
+
+    public function validate()
+    {
+        return in_array($this->timezone, timezone_identifiers_list());
+    }
+
+}