Manual trigger for steps running in parallel

#!python

- step:
      name: Step 0
      script:
          - echo "Automatic step 0";
- parallel:
      - step:
            name: Step 1
            script:
              - echo "Automatic step 1";
      - step:
            name: Step 2
            trigger: manual
            script:
              - echo "I need to click the button to execute Step 2";
      - step:
            name: Step 3
            script:
              - echo "Automatic step 3";