Update test_trunk after adding new ip command tool.

A new tool has been added to wrap with ip command
line tool.

https://review.openstack.org/#/c/613310/

This tool implements methods to list VM adrresses
and to configure VLAN device interfaces via an
SSH connection.

This refactor trunk test case to improve code
readability and make this test to use shared code
base with other test cases to be written in the
future related with trunk related scenarios.

Change-Id: I61563b7132f9911ad588d35f7f01125ef4c70cd2
1 file changed