[api tests] update pipeline tests to grab id from object keys instead…

… of array index

test/unit/api/ingest/_post.js

@@ -175,7 +175,7 @@ define(function (require) {
               method: 'GET'
             })
             .then(function (body) {
-              expect(body.pipelines[0].id).to.be('kibana-logstash-*');
+              expect(body).to.have.property('kibana-logstash-*');
             });
           });
       });