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/UsageResource.php

@@ -0,0 +1,20 @@
+<?php
+
+/** 
+ * Parent class for all UsageRecord subclasses
+ * @author Kevin Burke <kevin@twilio.com>
+ * @license  http://creativecommons.org/licenses/MIT/ MIT
+ * @link     http://pear.php.net/package/Services_Twilio
+ */
+class Services_Twilio_UsageResource extends Services_Twilio_ListResource {
+    public function getResourceName($camelized = false) {
+        $this->instance_name = 'Services_Twilio_Rest_UsageRecord';
+        return $camelized ? 'UsageRecords' : 'usage_records';
+    }
+
+    public function __construct($client, $uri) {
+        $uri = preg_replace("#UsageRecords#", "Usage/Records", $uri);
+        parent::__construct($client, $uri);
+    }
+}
+