This is a Bug Report
Is not a bug, but I think this is feature.

Problem:
In version 1.15.0 kubernetes does not return error, how writing in documentation:

In a second terminal, recreate the StatefulSet. Note that, unless you deleted the nginx Service ( which you should not have ), you will see an error indicating that the Service already exists.

kubectl apply -f web.yaml
statefulset.apps/web created
Error from server (AlreadyExists): error when creating "web.yaml": services "nginx" already exists

Proposed Solution:
I think need update documentation for 1.15.0 version and add next response if user install 1.15.0 version:

kubectl apply -f web.yaml
service/nginx unchanged
statefulset.apps/web created

Page to Update:
https://kubernetes.io/docs/tutorials/stateful-application/basic-stateful-set/

Kubernetes Version:
Client Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.0", GitCommit:"e8462b5b5dc2584fdcd18e6bcfe9f1e4d970a529", GitTreeState:"clean", BuildDate:"2019-06-21T13:09:06Z", GoVersion:"go1.12.6", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.0", GitCommit:"e8462b5b5dc2584fdcd18e6bcfe9f1e4d970a529", GitTreeState:"clean", BuildDate:"2019-06-19T16:32:14Z", GoVersion:"go1.12.5", Compiler:"gc", Platform:"linux/amd64"}

Additional Information:
Linux tester-tester 4.15.0-54-generic #58-Ubuntu SMP Mon Jun 24 10:55:24 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux