Remove server_groups_client from ignore_list
Remove server_groups_client from ignore_list

I75307176c2f032301da6227249070c42af54dd6e has fixed the method of
server_groups_client module which was against T110 rule.
So server_groups_client is not necessary in the ignore_list, then
this patch removes it.

Partially implements blueprint consistent-service-method-names

Change-Id: Iaa969235491d0ff7104c092c7728d8e5f66b2e9b

Juniper/tempest,LIS/lis-tempest,sebrandon1/tempest,bigswitch/tempest,openstack/tempest,zsoltdudas/lis-tempest,bigswitch/tempest,Tesora/tesora-tempest,masayukig/tempest,openstack/tempest,vedujoshi/tempest,vedujoshi/tempest,cisco-openstack/tempest,cisco-openstack/tempest,zsoltdudas/lis-tempest,LIS/lis-tempest,masayukig/tempest,sebrandon1/tempest,Juniper/tempest,Tesora/tesora-tempest