Respect auth.allow_tenant_isolation

Do not unconditionally use IsolatedCreds.

Closes-Bug: #1397244
Change-Id: I39f7e488dd6d649d2279f739f7da1076fea03ca0
diff --git a/tempest/api/image/base.py b/tempest/api/image/base.py
index 74baba6..76b6f17 100644
--- a/tempest/api/image/base.py
+++ b/tempest/api/image/base.py
@@ -15,7 +15,7 @@
 import cStringIO as StringIO
 
 from tempest import clients
-from tempest.common import isolated_creds
+from tempest.common import credentials
 from tempest.common.utils import data_utils
 from tempest import config
 from tempest import exceptions
@@ -36,7 +36,7 @@
         super(BaseImageTest, cls).resource_setup()
         cls.created_images = []
         cls._interface = 'json'
-        cls.isolated_creds = isolated_creds.IsolatedCreds(
+        cls.isolated_creds = credentials.get_isolated_credentials(
             cls.__name__, network_resources=cls.network_resources)
         if not CONF.service_available.glance:
             skip_msg = ("%s skipped as glance is not available" % cls.__name__)
diff --git a/tempest/api/object_storage/base.py b/tempest/api/object_storage/base.py
index 2e39cf9..7fabb7d 100644
--- a/tempest/api/object_storage/base.py
+++ b/tempest/api/object_storage/base.py
@@ -16,8 +16,8 @@
 
 from tempest.api.identity import base
 from tempest import clients
+from tempest.common import credentials
 from tempest.common import custom_matchers
-from tempest.common import isolated_creds
 from tempest import config
 from tempest import exceptions
 import tempest.test
@@ -34,7 +34,7 @@
         if not CONF.service_available.swift:
             skip_msg = ("%s skipped as swift is not available" % cls.__name__)
             raise cls.skipException(skip_msg)
-        cls.isolated_creds = isolated_creds.IsolatedCreds(
+        cls.isolated_creds = credentials.get_isolated_credentials(
             cls.__name__, network_resources=cls.network_resources)
         # Get isolated creds for normal user
         cls.os = clients.Manager(cls.isolated_creds.get_primary_creds())