Added Azure Batch ARM functions

[brnleehng]

Added Batch functions to AzureSMR

• Create Batch accounts
• Delete Batch accounts
• Get Batch account keys
• List Batch accounts

[msftclas]

@brnleehng,
Thanks for your contribution as a Microsoft full-time employee or intern. You do not need to sign a CLA.
Thanks,
Microsoft Pull Request Bot

[andrie]

Thank you for this contribution! This will really enhance the package.

Observations:

• Can you please add unit tests?
• Can you please modify your code to use the call_azure_sm() function? This simplifies the some redundant steps that you otherwise ahve to make. See the HDI code for an example