*What version of crane are you running, and what are your clutsters+platform*
0.0.4 dev

*What did you expect to happen?*
There's no way to override the transfer-pvc image.

*What actually happened?*
There's no way to override the transfer-pvc (rsync) pod. This means it always pulls from quay.

*Please include any relevant logs or errors*
It looks like crane-lib has a default set that can be overridden, but it is not exposed in crane.

I think we need to roughly approximate the tunnel-api options:
```
--destination-image string The container image to use on the destination cluster. Defaults to quay.io/konveyor/openvpn:latest
--source-image string The container image to use on the source cluster. Defaults to quay.io/konveyor/openvpn:latest
```

This will be important for downstream as well, since we'll probably have many cases where pulling from quay is not desired or even possible.