- Telco usecases requires a flavor which has to contain "extra_specs"
to boot a dpdk instance.
Add the "FLAVOR_NAME" parameter to override the use of the default
flavor used during migration flow.
- Modify the hardcoded server user name (cirros) to use the
"SERVER_USER_NAME" environment variable.
Change-Id: I3d50526d3192cafb673092bc8b22da6c48454434