gocd pipeline creation fail

* gocd_pipeline_stage.test: Received HTTP Status '422 Unprocessable Entity': '{
  "message": "Validations failed for pipeline 'test-pipeline3'. Error(s): [Validation failed.]. Please correct and resubmit.",
  "data": {
    "_links": {
      "self": {
        "href": "http://127.0.0.1:8153/go/api/admin/pipelines/test-pipeline3"
      },
      "doc": {
        "href": "https://api.gocd.org/#pipeline-config"
      },
      "find": {
        "href": "http://127.0.0.1:8153/go/api/admin/pipelines/:pipeline_name"
      }
    },
    "label_template": "${COUNT}",
    "enable_pipeline_locking": false,
    "name": "test-pipeline3",
    "template": null,
    "origin": null,
    "parameters": [

    ],
    "environment_variables": [

    ],
    "materials": [
      {
        "type": "git",
        "attributes": {
          "url": "https://github.com/drewsonne/terraform-provider-gocd.git",
          "destination": null,
          "filter": null,
          "invert_filter": false,
          "name": null,
          "auto_update": true,
          "branch": "master",
          "submodule_folder": null,
          "shallow_clone": false
        }
      }
    ],
    "stages": [
      {
        "name": "test",
        "fetch_materials": false,
        "clean_working_directory": false,
        "never_cleanup_artifacts": false,
        "approval": {
          "type": "",
          "authorization": {
            "roles": [

            ],
            "users": [

            ]
          }
        },
        "environment_variables": [

        ],
        "jobs": [
          {
            "name": "test",
            "run_instance_count": null,
            "timeout": null,
            "environment_variables": [

            ],
            "resources": [

            ],
            "tasks": [
              {
                "type": "exec",
                "attributes": {
                  "run_if": [
                    "success"
                  ],
                  "on_cancel": null,
                  "command": "echo",
                  "arguments": [
                    "test"
                  ],
                  "working_directory": null
                }
              }
            ],
            "tabs": [

            ],
            "artifacts": [

            ],
            "properties": null
          }
        ]
      }
    ],
    "tracking_tool": null,
    "timer": null
  }
}
'