Missing options in Swagger that are available in the Portal.

**Is your feature request related to a problem? Please describe.**
I would like to create a Python3 Azure Automation Runbook through Terraform. Since Terraform uses this API to build its provider I would like to request an enhancement to RunbookProperties so Terraform can accept Python or Python3 as Runbook types.

**Describe the solution you'd like**
I would like the [RunbookProperties runbookType enum in the Rest API](https://github.com/Azure/azure-rest-api-specs/blob/782bab9c34014092f48de95874a71e7ecd1a9bba/specification/automation/resource-manager/Microsoft.Automation/stable/2019-06-01/runbook.json#L1154) to include Python and Python3 as options. I notice the runbookTypeEnum is built in 3 other places in the Swagger as well. Please do what is needed to update all of those enums. This would allow the Terraform provider team to add the options for these runbook types to their resource in the azurerm provider.

**Describe alternatives you've considered**
If I cannot terraform something it does not exist. Until this option can be found in the Terraform provider I am stuck using PowerShell in Azure Automation.

**Additional context**
This feature is required to fix [this issue](https://github.com/hashicorp/terraform-provider-azurerm/issues/1602).

Start with specification/automation/resource-manager/Microsoft.Automation/stable/2019-06-01/runbook.json at the RunbookProperties runbookType enum, then search that file for the other runbookTypeEnum definitions. Update all four enums to include Python and Python3, and validate the REST specification before confirming the Terraform provider can discover the new values.

Written by the indexing model from the issue text.