Operator tests have an unversioned depenency on kudobuilder/operators

[asekretenko]

What happened:
After kudobuilder/operators#311 got merged, operator tests are failing (due to nonexistent operator referenced in one more file that was missed in that PR and is used only in KUDO tests)

What you expected to happen:
That no changes external to kudobuilder/kudo break tests in kudobuilder/kudo

How to reproduce it (as minimally and precisely as possible):
make operator-test (at least, until kudobuilder/operators#314 is merged)

Anything else we need to know?:

Environment:

• Kubernetes version (use kubectl version):
• Kudo version (use kubectl kudo version):
• Operator:
• operatorVersion:
• Cloud provider or hardware configuration:
• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a):
• Install tools:
• Others: