Draft: Allow the use of a token for git updates of rules

The goal of this change is to allow using git with a token to pull down rules from the runbooks repository.

Summary of changes so far:

• Update Gemfile, Berksfile, and Kitchen files to get kitchen tests working for testing
• Add a new attribute that defaults to nil for the token value.
• Stub out the get secrets for that token.
• Add code to only use the token if it exists.