Increase test coverage

[ritazh]

What steps did you take and what happened:
[A clear and concise description of what the bug is.]

Test coverage is currently ~50% #2604 (comment)

What did you expect to happen:

Let's increase it to 75%.

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]

Environment:

• Gatekeeper version:
• Kubernetes version: (use kubectl version):

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.