anchor.diff:                      "created_at": "2014-03-20T06:23:12Z",
                       "updated_at": "2014-04-21T08:22:22Z",
                       "links": {
  -                        "user" : "30",
  -                        "collection": "11"
  +                        "collection": "11",
  +                        "owner": {
  +                            "id": "4",
  +                            "type": "user_groups",
  +                            "href"=>"user_groups/4"
  +                        }
                       }
                   }]
               }
  
positive.code:                     "created_at": "2014-08-20T06:23:12Z",
                      "updated_at": "2014-09-21T08:22:22Z",
                      "links": {
                          "user" : "33",
                          "collection": "81"
                      }
                  }]
              }
  
negative.code:                     "roles": ["collaborator"],
                      "links": {
                          "project": "1",
                          "owner": {
                              "id": "842",
                              "type": "users",
                              "href": "users/842"
                          }
                      }
                  }
              }
  