Add list and update service tests to tempest

Registered by Ravikumar Venkatesan

The following two tests to be added to Tempest.
    List services - To be added
    Update services - To be added

The following tests already exist:
------------------------------------
 Create services - - - Already test exist
 Get a service - - - Already test exist
 Delete Service - - Already test exist

Blueprint information

Status:
Complete
Approver:
Ravikumar Venkatesan
Priority:
Medium
Drafter:
None
Direction:
Approved
Assignee:
Ravikumar Venkatesan
Definition:
Approved
Series goal:
Accepted for havana
Implementation:
Implemented
Milestone target:
milestone icon havana-2
Started by
Ravikumar Venkatesan
Completed by
Ravikumar Venkatesan

Related branches

Sprints

Whiteboard

Addressed by: https://review.openstack.org/20420
    Testcase for keystone - List services

Gerrit topic: https://review.openstack.org/#q,topic:bp/keystone-v3-service-api-test,n,z

Addressed by: https://review.openstack.org/22317
    Update service test case - V3

(?)

Work Items

Work items:
List services: DONE
Update services: DONE

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