0.9.0

Breaking

• CiderClient now is initialized with an optional UrlFetcher instead of a
  URLSessionConfiguration.
• More descriptive generic types for Resource.

Enhancements

• UrlFetcher provides an abstraction for URL loading so that users can choose
  their own mechanism: URLSession (default) or another (e.g. Alamofire).
• Add all current Storefronts.

Bug Fixes

• None