Remove monitor resource, its been replaced by metric_alert, outlier_alert and service_check
Refactor to be closer to the API; each resource creates exactly one resource (when not using count), instead oft 2, this removes much unneeded complexity. A warning threshold is now supported by the API.
Remove fuzzy resources like graph, and resources that used them -dashboard and screenboards. I'd welcome these resources, but the current state of Terraform and the Datadog API does not allow these to be implemented in a clean way.