Merge pull request #47 from hyonholee/dev

Dev
To fix DomainJoinSettings mapping issue: #2055
https://github.com/WindowsAzure/azure-sdk-tools/issues/2055
New-AzureVM fails when creating a VM with a Domain Join provisioning
Merge pull request #48 from huangpf/dev

To fix DomainJoinSettings mapping issue: #2055
Test bug fix.
Add a new test for New-AzureVM with DomainJoin