Add SMS support

Summary:
Provides a working SMS implementation with support for Twilio.

This version doesn't really retry if we get any gruff at all. Future versions should retry.

Test Plan: used bin/sms to send messages and look at them.

Reviewers: chad, epriestley

Reviewed By: epriestley

Subscribers: aurelijus, epriestley, Korvin

Maniphest Tasks: T920

Differential Revision: https://secure.phabricator.com/D8930

externals/twilio-php/Services/Twilio/Rest/CredentialLists.php

@@ -0,0 +1,24 @@
+<?php
+
+class Services_Twilio_Rest_CredentialLists extends Services_Twilio_SIPListResource {
+
+    /**
+     * Creates a new CredentialList instance
+     *
+     * Example usage:
+     *
+     * .. code-block:: php
+     *
+     *      $client->account->sip->credential_lists->create("MyFriendlyName");
+     *
+     * :param string $friendly_name: the friendly name of this credential list
+     * :param array $params: a single array of parameters which is serialized and
+     *      sent directly to the Twilio API.
+     */
+    public function create($friendly_name, $params = array()) {
+        return parent::_create(array(
+            'FriendlyName' => $friendly_name,
+        ) + $params);
+    }
+
+}