anchor.diff:  
   + Parameters
       + scenario_slug (string, `scenario_one`) ... Scenario slug
  -    + id (integer, 2) ... An unique identifier of the Step.
  +    + id (required,number,`2`) ... An unique identifier of the Step.
   
   
   + Request (application/json)
  
positive.code:               "links": [
                  {
                    "rel": [ "self" ],
                    "href": "http://example.com/scenarios/scenario_one/steps/1
                  }
                ],
                "rel": [ "item" ]
  
negative.code:     + page (string, `1`) ... Page result number.
      + sort (string, `name`) ... Attribute to sort by.
  
  
  + Response 200 (application/vnd.siren+json; charset=utf-8)
  
          {
  