packer-plugin-azure does not remove the datadisk after image creation

[John Trump]

packer-plugin-azure does not remove the datadisk after image creation. 

Scenario:

• Building image in an existing azure resource group
• Adding 200GB datadisk which is automatically named with prefix pkrdd, then a random string and ending with -1. For example - ( pkrdd327zb3txgw-1 )
• After image creation and cleanup the temporary vm, nic, osdisk, etc. are removed but the datadisk remains. 

How can the randomly named temporary datadisk be deleted?

[Mike Schinkel]

Can you share your packer script (with any sensitive information redacted, of course?)