Cronjob implementation in the tutorial not works

[camilamacedo86]

The following error is faced when we try to run the make tests with.

• Failure [0.137 seconds]
CronJob controller
/Users/camilamacedo/go/src/sigs.k8s.io/kubebuilder/docs/book/src/cronjob-tutorial/testdata/project/controllers/cronjob_controller_test.go:53
  When updating CronJob Status
  /Users/camilamacedo/go/src/sigs.k8s.io/kubebuilder/docs/book/src/cronjob-tutorial/testdata/project/controllers/cronjob_controller_test.go:66
    Should increase CronJob Status.Active count when new Jobs are created [It]
    /Users/camilamacedo/go/src/sigs.k8s.io/kubebuilder/docs/book/src/cronjob-tutorial/testdata/project/controllers/cronjob_controller_test.go:67

    Expected success, but got an error:
        <*errors.StatusError | 0xc0004d8780>: {
            ErrStatus: {
                TypeMeta: {Kind: "", APIVersion: ""},
                ListMeta: {
                    SelfLink: "",
                    ResourceVersion: "",
                    Continue: "",
                    RemainingItemCount: nil,
                },
                Status: "Failure",
                Message: "namespaces \"test-cronjob-namespace\" not found",
                Reason: "NotFound",
                Details: {
                    Name: "test-cronjob-namespace",
                    Group: "",
                    Kind: "namespaces",
                    UID: "",
                    Causes: nil,
                    RetryAfterSeconds: 0,
                },
                Code: 404,
            },
        }
        namespaces "test-cronjob-namespace" not found

    /Users/camilamacedo/go/src/sigs.k8s.io/kubebuilder/docs/book/src/cronjob-tutorial/testdata/project/controllers/cronjob_controller_test.go:100
------------------------------
STEP: By creating a new CronJob
2020-09-14T13:12:54.617+0100	INFO	controller-runtime.manager	starting metrics server	{"path": "/metrics"}
2020-09-14T13:12:54.617

[gabbifish]

/assign @gabbifish