Error in Postgres module

[grayjeremy]

The postgres module behaves differently in terraform 0.11.14 and 0.12. Error and input posted below. This issue is peeled off of #16

Error

Error: Missing resource instance key

  on .terraform\modules\demo_db\sjones-sot-terraform-azurerm-database-for-postgres-59b1e13\postgres.tf line 10, in resource "azurerm_postgresql_server" "postgresql_server":  10:   resource_group_name = "${var.resource_group_name == "" ? azurerm_resource_group.resource_group.name : var.resource_group_name}"
Because azurerm_resource_group.resource_group has "count" set, its attributes
must be accessed on specific instances.

For example, to correlate with indices of a referring resource, use:
    azurerm_resource_group.resource_group[count.index]

Input

module "demo_db" {
  source            = "sjones-sot/database-for-postgres/azurerm"
  resource_group_name = "${var.az_rg_name}"
  location          = "${var.az_region_default}"
  service_name      = "testdb"
  db_admin_password = "${var.az_fake_password}"
  sku_compute_units = 1
}