anchor.diff:  Create a Step
   
   + Parameters
  -    + scenario_slug (string, `scenario_one`) ... Scenario slug 
  +    + scenario_slug (string, `scenario_one`) ... Scenario slug
   
   + Request (application/json)
   
  
positive.code: 
  + Parameters
      + scenario_slug (string, `scenario_one`) ... Scenario slug
      + id (integer, 2) ... An unique identifier of the Step.
  
  
  + Request (application/json)
  
negative.code: Retrieve all POIs
  
  + Parameters
      + scenario_slug (string, `scenario_one`) ... Scenario slug
      + number (string, `10`) ... Amount of steps to show.
  
  + Response 200 (application/vnd.siren+json; charset=utf-8)
  