title: How do you cancel a previous 'running' spinnaker execution when starting a new execution
body: <p>We have a pipeline in Spinnaker that asks for manual judgement.</p>
  
  <p>There is the possible scenario that developers push a new build, but it does not proceed as the existing pipeline (Waiting for the manual judgement) is still running. We would like a way to have this older execution get cancelled when the newer one is created.</p>
  
  <p>There is the option of allowing multiple concurrent executions, but then it's possible that the developers will click the judgement step for the wrong one.</p>
  
  <p>How would you go about either cancelling existing running executions on a new run (You can only cancel older queued ones using documented options available in the GUI), or including a stage in your pipeline that first looks for and cancels existing running executions.</p>