* Leverage existance check in Compliance::Fetcher.resolve to not re-download locally cached profiles
* Move logic from Compliance::API.exist? to Compliance::API.profiles to reuse code in cases where we need to access profiles' metadata directly.
* Declare @upstream_sha256 if target is a string
* Handle other fetchers that don't support upstream_sha256 within Inspec::CachedFetcher.initialize
* Add initialize for Compliance::Fetcher to not pollute Fetchers::Url with its logic
* Add Compliance::Fetcher.sha256 to leverage upstream_sha256 instead of relying on inherited method from Fetchers::Url
* Revert changes to cached fetcher that are unnecessary after refactor
* Pacify the god of ruby syntax
* Move Compliance::API.profiles filtering logic to end of method to leverage normalization of mapped_profiles
* Add and update unit tests to support caching with Compliance::Fetcher.upstream_sha256
Signed-off-by: Josh Hudson <jhudson@chef.io>
