Able to add scheduled backups through the UI

bootstrap/helpers/constants.php

@@ -0,0 +1,10 @@
+<?php
+
+const DATABASE_TYPES = ['postgresql'];
+const VALID_CRON_STRINGS = [
+    'hourly' => '0 * * * *',
+    'daily' => '0 0 * * *',
+    'weekly' => '0 0 * * 0',
+    'monthly' => '0 0 1 * *',
+    'yearly' => '0 0 1 1 *',
+];