Refactor upload_file to instantiate and execute an Upload object.
Refactors Upload specs into a separate file.
Adds gzip option and uploading.
Fix gzip premature close warning.
Adds cache control through max_age option in config file.
Adds cache control info to README
Improve upload reporting to include details of gzip and cache control.
Adding specs for gzipping.
Adds gzip section to README
Merges in gzip, adds specs for cache control.