Move constants out of verify-cn script to a config file.

[felddy]

🗣 Description

This changes the constants to configuration file variables in the script used to query LDAP. There will be a sister PR in the Terraform module to create the configuration file at boot with cloudinit.

Closes #3

💭 Motivation and Context

This makes the server more configurable. Hard coding COOL values is not a best-practice.

🧪 Testing

Code tested in production with great success.

📷 Screenshots (if appropriate)

🚥 Types of Changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (causes existing functionality to change)

✅ Checklist

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed.