Fix interfaces response schema

After removing v3 schemas, we have only 1 set of schemas for v2 (/v2.1)
APIs but those end up in scattered structure.

Schema files needs to be re arranged into a clean structure. Any
resource schema should be defined in single file for better readability.

This patch merge the interfaces response schema into one file
Also define the schema for show and create os-interface API.

Partially implements blueprint rearrange-nova-response-schemas

Change-Id: I4ff75ef4d29304230a85aa224e43657e96b18f2e
diff --git a/tempest/services/compute/json/interfaces_client.py b/tempest/services/compute/json/interfaces_client.py
index 84a3271..c3bfa99 100644
--- a/tempest/services/compute/json/interfaces_client.py
+++ b/tempest/services/compute/json/interfaces_client.py
@@ -16,7 +16,6 @@
 import json
 import time
 
-from tempest.api_schema.response.compute import interfaces as common_schema
 from tempest.api_schema.response.compute import servers as servers_schema
 from tempest.api_schema.response.compute.v2_1 import interfaces as schema
 from tempest.common import service_client
@@ -46,17 +45,19 @@
         resp, body = self.post('servers/%s/os-interface' % server,
                                body=post_body)
         body = json.loads(body)
+        self.validate_response(schema.get_create_interfaces, resp, body)
         return service_client.ResponseBody(resp, body['interfaceAttachment'])
 
     def show_interface(self, server, port_id):
         resp, body = self.get('servers/%s/os-interface/%s' % (server, port_id))
         body = json.loads(body)
+        self.validate_response(schema.get_create_interfaces, resp, body)
         return service_client.ResponseBody(resp, body['interfaceAttachment'])
 
     def delete_interface(self, server, port_id):
         resp, body = self.delete('servers/%s/os-interface/%s' % (server,
                                                                  port_id))
-        self.validate_response(common_schema.delete_interface, resp, body)
+        self.validate_response(schema.delete_interface, resp, body)
         return service_client.ResponseBody(resp, body)
 
     def wait_for_interface_status(self, server, port_id, status):