Describe the bug
When working with path mappings in arr services, viper is forcing the key case to lowercase, violating the YAML spec. This is causing issues with checkrr being unable to find the files in arr services.

To Reproduce
Steps to reproduce the behavior:

1. set an arr service's path mapping to have capital letters in the path.
2. run checkrr with the config and the --debug flag
3. observe checkrr reading the path mapping key as a lowercase value in the debug output.

Expected behavior
Map key case should be respected.

Screenshots
n/a

Desktop (please complete the following information):

• OS: all
• Browser: all
• checkrr Version: >=3.1

Additional context
See spf13/viper#373 and spf13/viper#1014