Add pear modules, mail and net_smtp via composer (#93)

Add pear modules, mail and net_smtp via composer, remove php 5.6 build due to phpunit 6

lib/composer/vendor/phar-io/manifest/src/values/Url.php

@@ -0,0 +1,47 @@
+<?php
+/*
+ * This file is part of PharIo\Manifest.
+ *
+ * (c) Arne Blankerts <arne@blankerts.de>, Sebastian Heuer <sebastian@phpeople.de>, Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace PharIo\Manifest;
+
+class Url {
+    /**
+     * @var string
+     */
+    private $url;
+
+    /**
+     * @param string $url
+     *
+     * @throws InvalidUrlException
+     */
+    public function __construct($url) {
+        $this->ensureUrlIsValid($url);
+
+        $this->url = $url;
+    }
+
+    /**
+     * @return string
+     */
+    public function __toString() {
+        return $this->url;
+    }
+
+    /**
+     * @param string $url
+     *
+     * @throws InvalidUrlException
+     */
+    private function ensureUrlIsValid($url) {
+        if (filter_var($url, \FILTER_VALIDATE_URL) === false) {
+            throw new InvalidUrlException;
+        }
+    }
+}