Detect non-standard naming of the license file

[tas50]

What category of cop is this?:

Please try to select as few as possible.

• [ ] Deprecation - A cop that alerts to a deprecation in the Chef Infra Client
• [ ] Correctness - A cop that alerts when incorrect coding behavior is being used
• [ ] Sharing - A cop that alerts to missing functionality necessary for sharing cookboooks with others
• [x] Style - A cop that alerts to a style best practice
• [ ] Simplification - A cop that alerts to ways code can be simplified through refactoring
• [ ] Effortless - A cop that alerts on code that must be resolved to move to the Effortless pattern
• [ ] Policyfiles - A cop that alerts on code that must be resolved to move to the Policyfiles pattern

Describe the new cop:

License file location should be consistent to help setups like Github easily parse the contents and to make it easier for users to know where the file will always be.

What it would trigger on:

cookbook/license.txt cookbook/license

What it would autocorrect to if applicable

cookbook/LICENSE