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/pear/net_socket/README.md

@@ -0,0 +1,43 @@
+# Net_Socket - Network Socket Interface
+
+[![Build Status](https://travis-ci.org/pear/Net_Socket.svg?branch=master)](https://travis-ci.org/pear/Net_Socket)
+    
+
+Net_Socket is a class interface to TCP sockets. It provides blocking
+and non-blocking operation, with different reading and writing modes
+(byte-wise, block-wise, line-wise and special formats like network
+byte-order ip addresses).
+
+[Homepage](http://pear.php.net/package/Net_Socket/)
+
+
+## Installation
+For a PEAR installation that downloads from the PEAR channel:
+
+`$ pear install pear/net_socket`
+
+For a PEAR installation from a previously downloaded tarball:
+
+`$ pear install Net_Socket-*.tgz`
+
+For a PEAR installation from a code clone:
+
+`$ pear install package.xml`
+
+For a local composer installation:
+
+`$ composer install`
+
+To add as a dependency to your composer-managed application:
+
+`$composer require pear/net_socket`
+
+
+## Tests
+Run  the tests from a local composer installation:
+
+`$ ./vendor/bin/phpunit`
+
+
+## License
+BSD-2 license