Add no_ssl_peer_verification option

This allows the user to disable ssl peer certificate verification, which is usefull when the target server uses WinRM with a self-signed cert, or a cert that doesn't match the server's hostname.

This commit works with commits to the WinRM (https://github.com/gswallow/WinRM/commit/f4ece4384df2768bc7756c3c5c336db65b05c674) and knife-windows (https://github.com/gswallow/knife-windows/commit/d04c835cfff1260017b91a799168e90b931cad6a) gems.