Description:
------------
Stomp module seems not initializing SSL library first.  When creating a ssl 
connection like this:

    $stomp = new Stomp('ssl://localhost:61612');

will get the error:

    Failed to create the SSL context

Proposed patch is attached, please check it.  Thanks!

Test script:
---------------
<?php

$queue  = '/topic/foo';
$msg    = 'bar';

try {
    $stomp = new Stomp('ssl://localhost:61612');
    $stomp->send($queue, $msg." ". date("Y-m-d H:i:s"));
} catch(StompException $e) {
    die('Connection failed: ' . $e->getMessage());
}

?>

Expected result:
----------------
(The connection should successfully established and message should be successfully 
sent.)

Actual result:
--------------
Connection failed: failed to create the SSL context