v1.2.0-preview0001

[v1.2.0-preview0001]

Changed

• Update sample labs for Windows Server 2019 to use latest
  evaluation ISO download URIs and edition names.
• Removed sample samples\Sample_WS2019_NanoDomain.xml because it
  is not valid for Windows Server 2019.
• Improve structure of Invoke-LabSample.ps1 function to remove need
  for $script scope variables.
• Fixed sample samples\Sample_WS2019_AzureADConnect.xml default gateway
  for SA-AADC VM.
• dsclibrary\MEMBER_AADC.DSC.ps1: Created DSC config for deploying an
  Azure AD Connect server.