Add a services blacklist regex

[ryan-lane]

It's possible that you don't want services created in confidant. This is especially true if you're running multiple confidant instances that are segregated by environment (development/staging/prod). In these cases maybe you'd like to disallow staging and development environment services from being created in production confidant so that users don't get confused. We should add a service blacklist regex so that we can say "^.staging.$" and "^.development.$" are disallowed.