CommandLineTask Firetask type

CommandLineTask.yaml

- fw_id: 1
  name: 90 rotated A
  spec:
    _tasks:
    - _fw_name: CommandLineTask
      command_spec:
        command: [convert, -swirl]
        letter: {source: letter}
        swirl angle:
          source: {type: data, value: 90}
        90 out:
          target: {type: path, value: /tmp}
      inputs: [swirl angle,letter]
      outputs: [90 out]
    letter: {type: path, value: /tmp/letter.png}