Added QueueManager to process background jobs

app/ServiceProvider/QueueProvider.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Kanboard\ServiceProvider;
+
+use Kanboard\Core\Queue\QueueManager;
+use Pimple\Container;
+use Pimple\ServiceProviderInterface;
+
+/**
+ * Class QueueProvider
+ *
+ * @package Kanboard\ServiceProvider
+ * @author  Frederic Guillot
+ */
+class QueueProvider implements ServiceProviderInterface
+{
+    /**
+     * Registers services on the given container.
+     *
+     * @param Container $container
+     */
+    public function register(Container $container)
+    {
+        $container['queueManager'] = new QueueManager($container);
+        return $container;
+    }
+}