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/consolidation/config/src/Loader/YamlConfigLoader.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Consolidation\Config\Loader;
+
+use Symfony\Component\Yaml\Yaml;
+
+/**
+ * Load configuration files, and fill in any property values that
+ * need to be expanded.
+ */
+class YamlConfigLoader extends ConfigLoader
+{
+    public function load($path)
+    {
+        $this->setSourceName($path);
+
+        // We silently skip any nonexistent config files, so that
+        // clients may simply `load` all of their candidates.
+        if (!file_exists($path)) {
+            $this->config = [];
+            return $this;
+        }
+        $this->config = (array) Yaml::parse(file_get_contents($path));
+        return $this;
+    }
+}