AzureRMR 1.0.0.9000

Significant interface changes

Allow authentication without having to create a service principal first, by leveraging the Azure CLI cross-platform app. It's still recommended to create your own SP for authentication, if possible.
New create_azure_login, get_azure_login and delete_azure_login functions to handle ARM authentication. While directly calling az_rm$new() will still work, it's recommended to use create_azure_login and get_azure_login going forward. Login credentials will be saved and reused for subsequent sessions (see below).
By default, use the latest stable API version when interacting with resources. az_resource$set_api_version gains a new argument stable_only which defaults to TRUE; set this to FALSE if you want the latest preview version.
Token acquisition logic substantially enhanced and moved to a new package, AzureAuth. get_azure_token now supports four authentication methods for obtaining tokens (client_credentials, authorization_code, device_code and resource_owner). Tokens are also automatically cached and retrieved for use in subsequent sessions, without needing the user to reauthenticate. See the AzureAuth documentation for more details.

Don't print empty fields for ARM objects.
Add optional etag field to resource object definition.
Add location argument to az_resource_group$create_resource method, rather than hardcoding it to the resgroup location.
Add wait argument when creating a new resource, similar to deploying a template, since some resources will return before provisioning is complete. Defaults to FALSE for backward compatibility.
Export is_azure_token.
Allow az_resource_group$deploy_template() to work without parameters arg (parameters folded into template itself).
Fix a bug that kept az_resource_group$delete_resource from deleting the resource.
New resource method az_resource$get_api_version to match set_api_version.