test_service_providers.test_service_providers_list runs unconditionally

[Isaku Yamahata]

test_service_providers.test_service_providers_list requires neutron service-type extension.
It's enabled by default from Newton. So by default it fails with mitaka(or older).

The test case needs to be skipped when service-type extension isn't enabled.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/411461

[Ghanshyam Mann (ghanshyammann)]

Thanks, actually on gate we did not catch this as devstack set this extension all the way since killo or older.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/411461
Committed: https://git.openstack.org/cgit/openstack/tempest/commit/?id=b787aa7d8b256a7970d02cac01f73dcf8fd56271
Submitter: Jenkins
Branch: master

commit b787aa7d8b256a7970d02cac01f73dcf8fd56271
Author: Isaku Yamahata <email address hidden>
Date: Thu Dec 15 10:50:55 2016 -0800

    test_service_providers: require service-type ext

    test_service_providers assumes that service-type api extension.
    So skip it when it's not enabled.

    Change-Id: I22a3f184b24b674bd085af455ef074932b742442
    Closes-bug: #1650351