Merge pull request #2401 from kubernetes-sigs/nit

📖 fix typo issue into controller test

Author: k8s-ci-robot

docs/book/src/cronjob-tutorial/testdata/project/controllers/cronjob_controller_test.go

@@ -1,5 +1,5 @@
 /*
-Ideally, we should have one `<kind>_conroller_test.go` for each controller scaffolded and called in the `suite_test.go`.
+Ideally, we should have one `<kind>_controller_test.go` for each controller scaffolded and called in the `suite_test.go`.
 So, let's write our example test for the CronJob controller (`cronjob_controller_test.go.`)
 */