Verify quotas attributes through Nova os-quota-sets API

This patch adds checks whether a response of Nova os-quota-sets
get/get defaultAPI
includes the attributes to block the backward incompatibility change
in the future.

The quotas response body of v2 API is the following:
{
    "quota_set": {
        "id": "231a1e7fd1b344f9874d0334d98b459c",
        "instances": 10,
        "cores": 20,
        "ram": 51200,
        "floating_ips": 10,
        "fixed_ips": -1,
        "metadata_items": 128,
        "injected_files": 5,
        "injected_file_content_bytes": 10240,
        "injected_file_path_bytes": 255,
        "key_pairs": 100,
        "security_groups": 10
        "security_group_rules": 20,
    }
}

The one of v3 API is the following:
{
    "quota_set": {
        "id": "231a1e7fd1b344f9874d0334d98b459c",
        "instances": 10,
        "cores": 20,
        "ram": 51200,
        "floating_ips": 10,
        "fixed_ips": -1,
        "metadata_items": 128,
        "key_pairs": 100,
        "security_groups": 10
        "security_group_rules": 20,
    }
}

Partially implements blueprint nova-api-attribute-test

Change-Id: I8a45ba601b92f17808227a4853a42e812a2a082e
diff --git a/tempest/services/compute/json/quotas_client.py b/tempest/services/compute/json/quotas_client.py
index 2fae927..9346183 100644
--- a/tempest/services/compute/json/quotas_client.py
+++ b/tempest/services/compute/json/quotas_client.py
@@ -15,6 +15,7 @@
 
 import json
 
+from tempest.api_schema.compute.v2 import quotas as schema
 from tempest.common import rest_client
 from tempest import config
 
@@ -35,6 +36,7 @@
             url += '?user_id=%s' % str(user_id)
         resp, body = self.get(url)
         body = json.loads(body)
+        self.validate_response(schema.quota_set, resp, body)
         return resp, body['quota_set']
 
     def get_default_quota_set(self, tenant_id):
@@ -43,6 +45,7 @@
         url = 'os-quota-sets/%s/defaults' % str(tenant_id)
         resp, body = self.get(url)
         body = json.loads(body)
+        self.validate_response(schema.quota_set, resp, body)
         return resp, body['quota_set']
 
     def update_quota_set(self, tenant_id, force=None,