Description of problem:
When you don't have storage in your RHEV, API still allows you to create VM
This VM can't be started, and it can't even be removed via UI

Version-Release number of selected component (if applicable):

How reproducible:
always

Steps to Reproduce:
1. Create RHEV setup without storage
2. Create VM via API

Actual results:
VM is created successfully

Expected results:
You shouldn't be able to create VM without storage

Additional info:
UI doesn't let you create VM when you don't have storage