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/version/README.md

@@ -0,0 +1,16 @@
+# Version
+
+Library for handling version information and constraints
+
+[![Build Status](https://travis-ci.org/phar-io/version.svg?branch=master)](https://travis-ci.org/phar-io/version)
+
+## Installation
+
+You can add this library as a local, per-project dependency to your project using [Composer](https://getcomposer.org/):
+
+    composer require phar-io/version
+
+If you only need this library during development, for instance to run your project's test suite, then you should add it as a development-time dependency:
+
+    composer require --dev phar-io/version
+