Refactor Backup as a class and move logging to separate class

Moves away from the procedural code flow by changing the backup
module into a class that performs the backup. Also separates the
logging of the results into a separate class.
Configurator: correct handling of default config file path

Apparently my solution of defaulting the config file path in the
parameters doesn't work the way I anticipated. This switches us
back to an explicit check to see if we need to use the default
config file path.
Use correct class method signature for refactored methods
Gemspec: check in updated spec to include HTTParty