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/gettext/languages/bin/export-plural-rules

@@ -0,0 +1,4 @@
+#!/usr/bin/env php
+<?php
+
+include 'export-plural-rules.php';