Store kube-forensics-worker image in private registry

[robbo10]

Is this a BUG REPORT or FEATURE REQUEST?:
FEATURE REQUEST
What happened:

Once you submit the podcheckpoint the forensics-controller-manager pod then spins up the job.batch/podcheckpoint, which in turn starts the pod/podcheckpoint.  This is currently coming from keikoproj/kube-forensics-worker

What you expected to happen:
We would like the keikoproj/kube-forensics-worker image to come from an internal registry to meet our security requirements.

How to reproduce it (as minimally and precisely as possible):
Submit the podcheckpoint

Anything else we need to know?:

Environment:

• kube-forensics version
• Kubernetes version :

$ kubectl version -o yaml

Other debugging information (if applicable):

• PodCheckpoint status:

$ kubectl describe -n forensics-system podcheckpoint <checkpoint-name>

• controller logs:

$ kubectl logs -n forensics-system <forensics-controller-manager pod>