Python tutorial should include a sample using a custom image

[skywalkerisnull]

The python sample files need to include an example of running with a custom VM image. The current documentation seems to require using additional Azure APIs (Azure Common Credentials) and creation of an Azure AD application and service. But when using all of those pieces, the pool fails to deploy without an error message (just a time out after 30mins).

[skywalkerisnull]

I have found a tutorial to use custom images: https://github.com/azurebigcompute/recipes/blob/master/Azure%20Batch/CustomImages/CustomImageCLI.md