Using a new security group in scenario tests

Instead of using the default security group - creating and
using a new security group in setup_network_and_server.
This should help when two tests are in the same class and have the
same tenant which can cause problems when one test is changing the
security group, adding rules etc.

Also adding resource cleanup in API tests base for security groups.

Change-Id: I4997bb48edf05402aa8135e3fd70e4c16cafb114
diff --git a/neutron/tests/tempest/api/base.py b/neutron/tests/tempest/api/base.py
index b308a31..3321ad4 100644
--- a/neutron/tests/tempest/api/base.py
+++ b/neutron/tests/tempest/api/base.py
@@ -109,6 +109,7 @@
         cls.admin_address_scopes = []
         cls.subnetpools = []
         cls.admin_subnetpools = []
+        cls.security_groups = []
 
     @classmethod
     def resource_cleanup(cls):
@@ -167,6 +168,11 @@
                 cls._try_delete_resource(cls.admin_client.delete_network,
                                          network['id'])
 
+            # Clean up security groups
+            for secgroup in cls.security_groups:
+                cls._try_delete_resource(cls.client.delete_security_group,
+                                         secgroup['id'])
+
             for subnetpool in cls.subnetpools:
                 cls._try_delete_resource(cls.client.delete_subnetpool,
                                          subnetpool['id'])