Remove BaseV*ImageAdminTest class

This commit removes BaseV1 and V2 ImageAdminTest classes. The usage
was removed in the previous commit[0]. So, we don't need to have these
class anymore.

[0] I9ccf070a12d24e63db5fb0f960c8be764b1b02dd

Change-Id: Ie99bf856000c596ddc797be6ac09d4f0fd6a9256
diff --git a/tempest/api/image/base.py b/tempest/api/image/base.py
index 7103d56..142e3c2 100644
--- a/tempest/api/image/base.py
+++ b/tempest/api/image/base.py
@@ -183,23 +183,3 @@
                                          disk_format='raw')
         self.addCleanup(self.client.delete_image, image['id'])
         return image['id']
-
-
-class BaseV1ImageAdminTest(BaseImageTest):
-    credentials = ['admin', 'primary']
-
-    @classmethod
-    def setup_clients(cls):
-        super(BaseV1ImageAdminTest, cls).setup_clients()
-        cls.client = cls.os_primary.image_client
-        cls.admin_client = cls.os_admin.image_client
-
-
-class BaseV2ImageAdminTest(BaseImageTest):
-    credentials = ['admin', 'primary']
-
-    @classmethod
-    def setup_clients(cls):
-        super(BaseV2ImageAdminTest, cls).setup_clients()
-        cls.client = cls.os_primary.image_client_v2
-        cls.admin_client = cls.os_admin.image_client_v2