Adding description for testcases - volume part2

When Tempest is used in customer site, often we are required to
provide a testcase list including testcase names and descriptions.
Now no this kind of doc is available, so we can add descriptions
with the format of doc string for every testcase, so later we
can generata such a testcase description list.

There are hundreds of testcases missing descriptions, so we can
add them gradually, and limit the modified files in one patch
for the convenience of reviewing.

Change-Id: I8577ceddcc99f77cfa091519d1466f075de54e43
partially-implements: blueprint testcase-description
diff --git a/tempest/api/volume/admin/test_volume_pools.py b/tempest/api/volume/admin/test_volume_pools.py
index 744bc01..9424994 100644
--- a/tempest/api/volume/admin/test_volume_pools.py
+++ b/tempest/api/volume/admin/test_volume_pools.py
@@ -21,6 +21,8 @@
 
 
 class VolumePoolsAdminTestsJSON(base.BaseVolumeAdminTest):
+    """Test getting volume pools by admin users"""
+
     def _assert_pools(self, with_detail=False):
         cinder_pools = self.admin_scheduler_stats_client.list_pools(
             detail=with_detail)['pools']
@@ -33,8 +35,10 @@
 
     @decorators.idempotent_id('0248a46c-e226-4933-be10-ad6fca8227e7')
     def test_get_pools_without_details(self):
+        """Test getting volume pools without detail"""
         self._assert_pools()
 
     @decorators.idempotent_id('d4bb61f7-762d-4437-b8a4-5785759a0ced')
     def test_get_pools_with_details(self):
+        """Test getting volume pools with detail"""
         self._assert_pools(with_detail=True)