Modifying VRRP testcases

1]. Added retry logic after VRRP is reconfigured
2]. Modified the testcase to re-configure VRRP on the VMs.
3]. In the ecmp_traffic file, added the check for the SVM status
4]. Re-ordered the verification od the SI and VN in servicechain/firewall/verify.py
5]. Skipped the SVN and RI check in case a SI exists

Change-Id: Idb5952f1c2c4d4d46b1a4ae34b88675ce74ba714
Merge "Modifying VRRP testcases" into R2.0