Comment 9 for bug 1720965

Reviewed: https://review.opencontrail.org/36711
Committed: http://github.com/Juniper/contrail-test-ci/commit/0bf4bac91303cb553cf6ca602643d2dea77990d6
Submitter: Zuul (<email address hidden>)
Branch: R4.1

commit 0bf4bac91303cb553cf6ca602643d2dea77990d6
Author: Vedu Joshi <email address hidden>
Date: Tue Oct 3 13:19:55 2017 +0530

Optimize svc chain cases a bit

* Reduce some repeated nova/contrail api calls which were taking time
* and use the info present in VMFixture
* Remove some duplicate code while getting tap intf of a svm using vrf
* In create_service_vms(), create all svms in one-shot and verify them
* together, which brings down execution time
* In config_svc_chain(), no need to verify left and right vms when they
* are passed as args

Change-Id: I5cad5dd4ea5ba10bde14aa39479b09c92b505ef3
Closes-Bug: 1720965
(cherry picked from commit 3e3cfb36707afa9a84e38b2bee12726f4b1bc1f9)