Added driver and unittests for CloudFront

What needs to happen here is Jira Story CDN-172 where we have the distribution_id stored, and that should be passed into the providers instead of service_name.  That will solve this overriding of variables that is causing ambiguity and confusion.

Lets focus on getting that story completed and then update this PR with the corresponding changes.  Sync up with @tonytan4ever on that change.