Near-term FutureProofing

No functional changes.
Removed Parameter validation for BaseOS image names. Input will be checked against current available images.
Added in some code to deal with the impending deprecation of the Get-EC2ImageByName Cmdlet in the AWSPowerShell module.

Windows 2019 Server and EC2Launch support

Install here: https://www.powershellgallery.com/packages/PackerBaseAMI/1.0.3

Added support for Windows Server 2019
Added support for EC2Launch. This module originally only worked with EC2Config.

EC2Launch is a set of Windows PowerShell scripts that replaces the EC2Config service on Windows Server 2016 and later AMIs. - https://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/ec2launch.html

This module now supports 2008, 2012, 2016 & 2019 Base AMIs.

Plan to add more options later to encompass the full range of AWS Managed Windows AMIs