Test Kitchen Windows Guest Support - Transport Mechanism

:construction: 

This PR is in the works and being created to collect some initial feedback. 

This PR applies @afiune's changes in https://github.com/test-kitchen/test-kitchen/pull/470 to `spec-coverage` branch of test-kitchen/test-kitchen and introduced a new `Transport` class that houses the SSH / WinRM specific logic. It also introduces a `CommonBase` driver which supports multiple transports. 

The idea behind this logic is to enable existing drivers to utilize the windows support in test-kitchen with a very simple change (demonstrated https://github.com/test-kitchen/kitchen-vagrant/pull/110). Of course any driver should add windows support for the logic they already contain.