Tempest test test_delete_role_request_without_token failed

Detailed bug description:
tempest.api.identity.admin.v2.test_roles_negative.RolesNegativeTestJSON.test_delete_role_request_without_token

Configuration:
Settings:
Compute - QEMU.
Network - Neutron with VLAN segmentation.
Storage Backends - LVM
Additional services - Install Ironic, Install Sahara

In tab Settings->Compute check Nova quotas
In tab Settings->OpenStack Services check enable Install Ceilometer and Aodh
In tab Networks->Other check enable Neutron DVR

Nodes: controller, compute, ironic,cinder, Telemetry - MongoDB

Steps to reproduce:
    1. Deploy ISO in configuration see (Detailed bug description)
    2. Navigate to controller node
    3. Install git (use apt-get install git)
    4. Clone script to deploy rally + tempest
       # git clone https://github.com/obutenko/mos-rally-verify.git
    5. Navigate to the https://github.com/obutenko/mos-rally-verify
    6. Execute necessary steps to deploy tempest
    7. Tun test in debug mode
        #rally --debug verify start --regex tempest.api.identity.admin.v2.test_roles_negative.RolesNegativeTestJSON.test_delete_role_request_without_token

Expected results:
Test is passed

Actual result:
Test is Failed
(see comments)

Reproducibility:
See attachment

Workaround:
---

Impact:
---

Description of the environment:
See (Detailed bug description)

Additional information:
Error Message

test failed

Stacktrace

Traceback (most recent call last):
  File "/home/rally/.rally/tempest/for-deployment-aac0638e-270e-44e8-bfd0-5c5bc95e1e0e/tempest/api/identity/admin/v2/test_roles_negative.py", line 109, in test_delete_role_request_without_token
    role_id)
  File "/usr/local/lib/python2.7/dist-packages/testtools/testcase.py", line 480, in assertRaises
    self.assertThat(our_callable, matcher)
  File "/usr/local/lib/python2.7/dist-packages/testtools/testcase.py", line 493, in assertThat
    raise mismatch_error
testtools.matchers._impl.MismatchError: <bound method RolesClient.delete_role of <tempest.services.identity.v2.json.roles_client.RolesClient object at 0x7f5f26c1e610>> returned ({'status': '204', 'content-length': '0', 'content-location': 'http://10.109.1.9:35357/v2.0/OS-KSADM/roles/c89cb9d4c0534681bdbb3aa4690caa39', 'vary': 'X-Auth-Token', 'server': 'Apache', 'connection': 'close', 'date': 'Sun, 15 May 2016 23:42:01 GMT', 'x-openstack-request-id': 'req-4badece7-2f14-49b6-9f32-5eeae8cf9eff'}, '')