Azure CLI - VMSS Preview

1. NPM Installation for the latest version:
   npm install -g https://github.com/AzureRT/azure-xplat-cli/archive/vmss.tar.gz

Note that it can also be installed under a local folder by omitting the -g option, then call node .\node_modules\azure-cli\bin\azure to start.

2. MSI Installation:
   Microsoft Azure Command Line Tools.msi