Move Cinder admin tests into unversioned path

As http://lists.openstack.org/pipermail/openstack-dev/2017-March/114507.html
we will use the existing Cinder V2 API tests for testing the base
microversion of Cinder V3 API also.
So it is not necessary to contain versioned path in test module pathes.
This patch just moves Cinder admin tests to unversioned pathes.

Change-Id: I2acfe5a28a2533b16565e6ebad5c820e7c3a3967
diff --git a/tempest/api/volume/admin/v2/test_backends_capabilities.py b/tempest/api/volume/admin/test_backends_capabilities.py
similarity index 100%
rename from tempest/api/volume/admin/v2/test_backends_capabilities.py
rename to tempest/api/volume/admin/test_backends_capabilities.py
diff --git a/tempest/api/volume/admin/v2/test_snapshot_manage.py b/tempest/api/volume/admin/test_snapshot_manage.py
similarity index 100%
rename from tempest/api/volume/admin/v2/test_snapshot_manage.py
rename to tempest/api/volume/admin/test_snapshot_manage.py
diff --git a/tempest/api/volume/admin/v3/test_user_messages.py b/tempest/api/volume/admin/test_user_messages.py
similarity index 100%
rename from tempest/api/volume/admin/v3/test_user_messages.py
rename to tempest/api/volume/admin/test_user_messages.py
diff --git a/tempest/api/volume/admin/v2/test_volume_pools.py b/tempest/api/volume/admin/test_volume_pools.py
similarity index 100%
rename from tempest/api/volume/admin/v2/test_volume_pools.py
rename to tempest/api/volume/admin/test_volume_pools.py
diff --git a/tempest/api/volume/admin/v2/test_volume_type_access.py b/tempest/api/volume/admin/test_volume_type_access.py
similarity index 100%
rename from tempest/api/volume/admin/v2/test_volume_type_access.py
rename to tempest/api/volume/admin/test_volume_type_access.py
diff --git a/tempest/api/volume/admin/v2/test_volumes_list.py b/tempest/api/volume/admin/test_volumes_list.py
similarity index 100%
rename from tempest/api/volume/admin/v2/test_volumes_list.py
rename to tempest/api/volume/admin/test_volumes_list.py
diff --git a/tempest/api/volume/admin/v2/__init__.py b/tempest/api/volume/admin/v2/__init__.py
deleted file mode 100644
index e69de29..0000000
--- a/tempest/api/volume/admin/v2/__init__.py
+++ /dev/null
diff --git a/tempest/api/volume/admin/v3/__init__.py b/tempest/api/volume/admin/v3/__init__.py
deleted file mode 100644
index e69de29..0000000
--- a/tempest/api/volume/admin/v3/__init__.py
+++ /dev/null