Added debug mode for cron run-builds command

[corpsee]

Contribution Type: feature/bugfix Link to Intent to Implement: - Link to Bug: -

This pull request affects the following areas:

• [ ] Front-End
• [X] Builder
• [ ] Build Plugins

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• [X] I have read and understood the contributing guidelines?
• [X] I have checked that another pull request for this purpose does not exist.
• [X] I have considered, and confirmed that this submission will be valuable to others.
• [X] I have created or updated the relevant documentation for this change on the PHPCI Wiki.
• [X] Do the PHPCI tests pass?

Detailed description of change: Added debug mode for cron run-builds command