update dependencies, add `license_finder`
configure `license_finder`
update `Rakefile` and `Guardfile` support files
update deprecated ChefSpec syntax:

* use `ChefSpec::SoloRunner`
add initial `Serverspec` integration test coverage
update copyright year
update CI, add `bundle-audit` and `license_finder`
Merge pull request #15 from phlipper/updates

Project Updates