Updating the official Ruby libraries

The official Ruby libraries Postmark and Postmark-Rails have been updated to version 1.0 and 0.5.0, respectively. The update brings improvements such as better integration with the Ruby community's new tools and frameworks, concurrency support, and a more modern architecture that allows for concurrent applications. The libraries now provide easier email sending capabilities, support for lesser-known Postmark API features, and improved testing with RSpec 2.0 and Travis-CI service.