Add some api ref links for network service clients

This patch just adds some api ref links for network service clients.

Change-Id: I49c7bc22a72237eca95733718d179196677635e6

tempest/lib/services/network/metering_label_rules_client.py

@@ -16,6 +16,12 @@
 class MeteringLabelRulesClient(base.BaseNetworkClient):
 
     def create_metering_label_rule(self, **kwargs):
+        """Create metering label rule.
+
+        For a full list of available parameters, please refer to the official
+        API reference:
+        https://developer.openstack.org/api-ref/network/v2/index.html#create-metering-label-rule
+        """
         uri = '/metering/metering-label-rules'
         post_data = {'metering_label_rule': kwargs}
         return self.create_resource(uri, post_data)
@@ -29,5 +35,11 @@ def delete_metering_label_rule(self, metering_label_rule_id):
         return self.delete_resource(uri)
 
     def list_metering_label_rules(self, **filters):
+        """List metering label rules.
+
+        For a full list of available parameters, please refer to the official
+        API reference:
+        https://developer.openstack.org/api-ref/network/v2/index.html#list-metering-label-rules
+        """
         uri = '/metering/metering-label-rules'
         return self.list_resources(uri, **filters)

tempest/lib/services/network/quotas_client.py

@@ -18,6 +18,12 @@
 class QuotasClient(base.BaseNetworkClient):
 
     def update_quotas(self, tenant_id, **kwargs):
+        """Update quota for a project.
+
+        For a full list of available parameters, please refer to the official
+        API reference:
+        https://developer.openstack.org/api-ref/network/v2/index.html#update-quota-for-a-project
+        """
         put_body = {'quota': kwargs}
         uri = '/quotas/%s' % tenant_id
         return self.update_resource(uri, put_body)

tempest/lib/services/network/service_providers_client.py

@@ -16,6 +16,11 @@
 class ServiceProvidersClient(base.BaseNetworkClient):
 
     def list_service_providers(self, **filters):
-        """Lists service providers."""
+        """Lists service providers.
+
+        For a full list of available parameters, please refer to the official
+        API reference:
+        https://developer.openstack.org/api-ref/network/v2/index.html#list-service-providers
+        """
         uri = '/service-providers'
         return self.list_resources(uri, **filters)