Allow kwargs in get_server_ip

As a part of the scenario/manager.py stabilization tracked by
the below BP the patch adds kwargs argument for get_server_ip
method so that the consumers are able to pass additional
parameters if needed.

Change-Id: I5741e16a8f2eac885d957d216a71b639e80775a8
Implements: blueprint tempest-scenario-manager-stable
1 file changed