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/myclabs/deep-copy/fixtures/f006/A.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace DeepCopy\f006;
+
+class A
+{
+    public $cloned = false;
+    private $aProp;
+
+    public function getAProp()
+    {
+        return $this->aProp;
+    }
+
+    public function setAProp($prop)
+    {
+        $this->aProp = $prop;
+
+        return $this;
+    }
+
+    public function __clone()
+    {
+        $this->cloned = true;
+    }
+}