Ordering of search paths for CODEOWNERS file

[mpapis]

codeowners-checker/lib/codeowners/checker.rb

Line 118 in 2115f48

directories = ['', '.github', 'docs', '.gitlab']

Github and Gitlab have different ideas on where to look for the CODEOWNERS file:

• https://help.github.com/en/articles/about-code-owners#codeowners-file-location
• https://docs.gitlab.com/ee/user/project/code_owners.html

Find out which order we should use and fix it, if necessary contact Github/Gitlab to fix the order.

It is possible we might need to check the repository remote(s) to decide on an order.

Another consideration is we might actually issue a warning if there are multiple files. (add tests for having multiple files)