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/f008/B.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace DeepCopy\f008;
+
+class B extends A
+{
+}