Merge branch 'add_cron' into 'develop'

feat: add cron for deleting 3 years old + ldc messages

See merge request ldc-web/projets/ldc!19

crons/DeleteLDCMessages.php

@@ -0,0 +1,15 @@
+<?php
+
+require_once(__DIR__ . '/../wp-load.php');
+
+
+function deleteOldLdcMessages()
+{
+    global $wpdb;
+
+    $wpdb->query(
+        $wpdb->prepare("DELETE FROM wp_messages WHERE `DATE` < CURDATE() - INTERVAL %d YEAR", 3)
+    );
+}
+
+deleteOldLdcMessages();