Write integration tests to test DAO for VM

[Krisilda]

1. Retrieve serviceOffering id, template id, zone id from CloudStack server.
2. Use a specific subclass of Request to create a request to get a non-existing entity.
3. Request the non-existing entity from 1st step through DAO (the empty list should be returned).
4. Use a specific subclass of Request to create a VM (use ids from first step).
5. Execute the request from the previous step through DAO.
6. Request the VM through DAO (need to check that fields specified with the parameters are equal to fields of received entity).
7. Create one more VM (repeat steps 4, 5).
8. Request a list of VM through DAO (need to check that fields specified with the parameters are equal to fields of received entities).