Test deployment computes with network in DPDK mode

We need to test compute nodes deployment with network interface in DPDK mode, and boot a VM with vhostuser and HugePages enabled.

Base test scenario for new cases is the following:

1. Create new environment with VLAN segmentation for Neutron
2. Add some nodes to cluster
3. Configure vhostuser (???)
4. Configure HugePages (???)
5. Configure private network in DPDK mode (???)
6. Run network verification
7. Deploy environment
8. Run network verification
9. Run OSTF
10. Create instance and boot it
11. Assign floating IP to it
12. Check that instance is reachable via floating IP
(???)
13. Reboot compute node
14. Create instance and boot it

Negative test cases are also need to be implemented:

 * DPDK can't be used with tunneling segmentation (GRE/VXLAN)
 * DPDK can't be enabled on interfaces which do not support this technology
 * DPDK should be used on dedicated network interface
 * DPDK can't be enabled if SR-IOV usage is activated (actual behavior is not clear from specification, so this point will be clarified) (???)
 * DPDK can't be enabled on non-compute nodes (actual behavior is not clear from specification, so this point will be clarified) (???)