add piwik installation

www/analytics/core/Updates/2.0-a17.php

@@ -0,0 +1,42 @@
+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ */
+namespace Piwik\Updates;
+
+use Piwik\Db;
+use Piwik\Filesystem;
+use Piwik\Updates;
+
+/**
+ */
+class Updates_2_0_a17 extends Updates
+{
+    public static function update()
+    {
+        $errors = array();
+
+        // Deleting old plugins
+        $obsoleteDirectories = array(
+            PIWIK_INCLUDE_PATH . '/plugins/Referers',
+            PIWIK_INCLUDE_PATH . '/plugins/PDFReports',
+        );
+        foreach ($obsoleteDirectories as $dir) {
+            if (file_exists($dir)) {
+                Filesystem::unlinkRecursive($dir, true);
+            }
+
+            if (file_exists($dir)) {
+                $errors[] = "Please delete this directory manually (eg. using your FTP software): $dir \n";
+            }
+
+        }
+        if(!empty($errors)) {
+            throw new \Exception("Warnings during the update: <br>" . implode("<br>", $errors));
+        }
+   }
+}