In Dixons folder, there's file for task 1. The Script. It's in bash and just sending info to Slack which I recommend in Task 2.

Task 2. The Queue is covered here: For a messaging system I recommend the Slack app. It's very popular application not only for standard messaging. It also supports file sharing, direct and group messaging tools. In addition, the app features a system of chat channels, allowing you to quickly set up subgroups for task or topic-oriented discussions. It also integrates other services so you can easily use it for alerts, reminders etc. It's a huge tool even with a free plan.

And task 3. The Consumer is in dixons api folder. There's a script in PHP Lumen framework commented inside the script. If you need wider comment I can provide it here as well. Script is written as is. Wasn't implemented anywhere and it's purpose is just to show the knowledge of PHP and MVC framework.