Move object storage account_client to lib interface

object storage account_client is stable now and good to be moved
as stable library interface.

Partially implements blueprint consistent-service-method-names

Change-Id: I03863fbb23e914b4115f2c0aaec0ecf266ccc060
diff --git a/releasenotes/notes/make-account-client-as-stable-interface-d1b07c7e8f17bef6.yaml b/releasenotes/notes/make-account-client-as-stable-interface-d1b07c7e8f17bef6.yaml
new file mode 100644
index 0000000..9d5a1f5
--- /dev/null
+++ b/releasenotes/notes/make-account-client-as-stable-interface-d1b07c7e8f17bef6.yaml
@@ -0,0 +1,9 @@
+---
+features:
+  - |
+    Define below object storage service clients as libraries.
+    Add new service clients to the library interface so the
+    other projects can use these modules as stable libraries
+    without any maintenance changes.
+
+      * account_client
diff --git a/tempest/services/object_storage/account_client.py b/tempest/lib/services/object_storage/account_client.py
similarity index 75%
rename from tempest/services/object_storage/account_client.py
rename to tempest/lib/services/object_storage/account_client.py
index 5a1737e..67f01a6 100644
--- a/tempest/services/object_storage/account_client.py
+++ b/tempest/lib/services/object_storage/account_client.py
@@ -50,41 +50,20 @@
         return resp, body
 
     def list_account_metadata(self):
-        """HEAD on the storage URL
-
-        Returns all account metadata headers
-        """
+        """List all account metadata."""
         resp, body = self.head('')
         self.expected_success(204, resp.status)
         return resp, body
 
     def list_account_containers(self, params=None):
-        """GET on the (base) storage URL
+        """List all containers for the account.
 
         Given valid X-Auth-Token, returns a list of all containers for the
         account.
 
-        Optional Arguments:
-        limit=[integer value N]
-            Limits the number of results to at most N values
-            DEFAULT:  10,000
-
-        marker=[string value X]
-            Given string value X, return object names greater in value
-            than the specified marker.
-            DEFAULT: No Marker
-
-        prefix=[string value Y]
-            Given string value Y, return object names starting with that prefix
-
-        reverse=[boolean value Z]
-            Reverse the result order based on the boolean value Z
-            DEFAULT: False
-
-        format=[string value, either 'json' or 'xml']
-            Specify either json or xml to return the respective serialized
-            response.
-            DEFAULT:  Python-List returned in response body
+        For a full list of available parameters, please refer to the official
+        API reference:
+        https://developer.openstack.org/api-ref/object-store/#show-account-details-and-list-containers
         """
         url = '?%s' % urllib.urlencode(params) if params else ''
 
diff --git a/tempest/services/object_storage/__init__.py b/tempest/services/object_storage/__init__.py
index a2f0992..771ed8f 100644
--- a/tempest/services/object_storage/__init__.py
+++ b/tempest/services/object_storage/__init__.py
@@ -12,11 +12,11 @@
 # License for the specific language governing permissions and limitations under
 # the License.
 
+from tempest.lib.services.object_storage.account_client import AccountClient
 from tempest.lib.services.object_storage.bulk_middleware_client import \
     BulkMiddlewareClient
 from tempest.lib.services.object_storage.capabilities_client import \
     CapabilitiesClient
-from tempest.services.object_storage.account_client import AccountClient
 from tempest.services.object_storage.container_client import ContainerClient
 from tempest.services.object_storage.object_client import ObjectClient