Add --use-encryption option for winrm

@adamedx  @NimishaS  @kaustubh-d 

Added changes for --use-encryption option. It will decide use of 'winrm-s' patch for winrm communication.

@adamedx 
I've added changes to raise an error on non-windows platform. 
But I think instead of raising error we can give warning for non-windows platform, which will continue command execution.  Anyways use of this flag doesn't have any impact on linux flow as we are checking platform first.

Thanks!