feature: Notify about failed updates, block detectable bad updates (#7188)

* Feature: Notify about failed updates, block detectable bad updates
Ability to post notifications when the update fails.
Detect and roll back updates that will cause broken installs. (Needs testing)
Add severity to notifications, critical (2) notifications will display a toast.

This will be used for removing in-tree dependencies and raising the minimum php version.

* Improve naming a bit add phpdoc to new_notification
In case multiple notifications are created, remove them all.

* Remove notifications when update is disabled.

* update travis to use db testing

* added missing index

daily.php

@@ -8,8 +8,9 @@
 
 $init_modules = array('alerts');
 require __DIR__ . '/includes/init.php';
+include_once __DIR__ . '/includes/notifications.php';
 
-$options = getopt('f:d:o:');
+$options = getopt('f:d:o:t:r:');
 
 if (isset($options['d'])) {
     echo "DEBUG\n";
@@ -97,8 +98,26 @@ if ($options['f'] === 'device_perf') {
     }
 }
 
+if ($options['f'] === 'set_notification') {
+    if ($options['t'] === 'update') {
+        $title = 'Error: Daily update failed';
+
+        if ($options['r']) {
+            remove_notification($title);
+        } else {
+            new_notification(
+                $title,
+                'The daily update script (daily.sh) has failed. Please check output by hand. If you need assistance, '
+                . 'visit the <a href="https://www.librenms.org/#support">LibreNMS Website</a> to find out how.',
+                2,
+                'daily.sh'
+            );
+        }
+    }
+}
+
 if ($options['f'] === 'notifications') {
-    include_once 'includes/notifications.php';
+    post_notifications();
 }
 
 if ($options['f'] === 'bill_data') {