Use a factory to Config and LocaleManager (see #298)

classes/LocaleManagerFactory.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Alltube;
+
+use Alltube\Exception\DependencyException;
+
+/**
+ * Class LocaleManagerFactory
+ * @package Alltube
+ */
+class LocaleManagerFactory
+{
+
+    /**
+     * @return LocaleManager|null
+     * @throws DependencyException
+     */
+    public static function create()
+    {
+        if (!class_exists('Locale')) {
+            throw new DependencyException('You need to install the intl extension for PHP.');
+        }
+
+        return LocaleManager::getInstance();
+    }
+}