Ruby Slack integration and cronjob for WRT with some information

[danieljames-dj]

This has two subtasks:

• Ruby Slack integration
• WRT cronjob with some information

Basically, what the cronjob has to do is, it has to check the length of Competition.pending_posting and if it is greater than 5, send a Slack notification to WRT saying that 'Number of pending competitions to be posted is greater than 5'.

For integrating Ruby Slack, the following link can be referred: https://www.rubyinrails.com/2015/09/14/rails-slack-integration-with-slack-notifier-gem/.

Also, it is suggested to store the webhook URL in a table named slack_webhook_url, so that we can extend the notification to more teams in future. For testing purpose, the developer can create their own slack URL, and the original WRT URL can be added manually to the database after the PR is merged.

Some helping articles to the developer interested in taking this:

• Ruby slack integration is completely explained in the link shared above.
• For creating table, you can check the migration doc here: https://guides.rubyonrails.org/active_record_migrations.html.
• For cronjobs, you can check in the codebase how other cronjobs are written.