Add health check email notifications

healthcheck

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+export $(grep -v '^#' /etc/reminder-rs/config.env | xargs -d '\n')
+
+VAR=$(mysql -N -D reminders -e "SELECT COUNT(1) FROM reminders WHERE utc_time < NOW() - INTERVAL 10 MINUTE AND enabled = 1")
+
+if [ "$VAR" -gt 0 ]
+then
+  echo "This is to inform that there is a reminder backlog which must be resolved." | mail -s "Backlog: $VAR" "$REPORT_EMAIL"
+fi