Enable protected branch for master

[mnaser]

❓ I'm submitting a ...

• [X] 🐞 bug report
• [ ] 🐣 feature request
• [ ] ❓ question about the decisions made in the repository

🐞 Describe the bug. What is the current behavior? The current master branch does not have any branch protection, it would be good to enable it in order for things like Zuul (#267 and #265) take advantage of it.

❓ What is the motivation / use case for changing the behavior? Better project hygiene overall and more native Zuul workflows.

💡 To Reproduce N/A

💡 Expected behavior N/A

📋 Details N/A

📋 Environment N/A

📋 Additional context N/A