[securemail] Update Composer dependencies

- Update phpseclib/phpseclib to version 2.0.4
- Update singpolyma/openpgp-php to version 0.3.0

securemail/vendor/singpolyma/openpgp-php/examples/sign.php

@@ -0,0 +1,22 @@
+<?php
+
+require_once dirname(__FILE__).'/../lib/openpgp.php';
+require_once dirname(__FILE__).'/../lib/openpgp_crypt_rsa.php';
+
+/* Parse secret key from STDIN, the key must not be password protected */
+$wkey = OpenPGP_Message::parse(file_get_contents('php://stdin'));
+$wkey = $wkey[0];
+
+/* Create a new literal data packet */
+$data = new OpenPGP_LiteralDataPacket('This is text.', array('format' => 'u', 'filename' => 'stuff.txt'));
+
+/* Create a signer from the key */
+$sign = new OpenPGP_Crypt_RSA($wkey);
+
+/* The message is the signed data packet */
+$m = $sign->sign($data);
+
+/* Output the raw message bytes to STDOUT */
+echo $m->to_bytes();
+
+?>