Tempest test for Neutron extension: extraroute-atomic

Change-Id: I9b104432f1cd1aa1471087226ffc53152b823222
Depends-On: https://review.opendev.org/670851
Partial-Bug: #1826396 (rfe)
Related-Change: https://review.opendev.org/655680 (spec)
diff --git a/neutron_tempest_plugin/api/base.py b/neutron_tempest_plugin/api/base.py
index 79ac4a6..71a0e5e 100644
--- a/neutron_tempest_plugin/api/base.py
+++ b/neutron_tempest_plugin/api/base.py
@@ -724,6 +724,14 @@
         return interface
 
     @classmethod
+    def add_extra_routes_atomic(cls, *args, **kwargs):
+        return cls.client.add_extra_routes_atomic(*args, **kwargs)
+
+    @classmethod
+    def remove_extra_routes_atomic(cls, *args, **kwargs):
+        return cls.client.remove_extra_routes_atomic(*args, **kwargs)
+
+    @classmethod
     def get_supported_qos_rule_types(cls):
         body = cls.client.list_qos_rule_types()
         return [rule_type['type'] for rule_type in body['rule_types']]