Security Group ICMP validation for icmp-code

This patch would ensure that Security Group rule creation would
fail when icmp-code alone is provided.

Partially implements: bp ipv6-api-testing-parity
Change-Id: Ib630a72b0979c9738c80cbb0df862bab10b30e5c
diff --git a/tempest/api/network/test_security_groups_negative.py b/tempest/api/network/test_security_groups_negative.py
index 97e4cb7..87267d6 100644
--- a/tempest/api/network/test_security_groups_negative.py
+++ b/tempest/api/network/test_security_groups_negative.py
@@ -138,6 +138,7 @@
 
         # Create rule for icmp protocol with invalid ports
         states = [(1, 256, 'Invalid value for ICMP code'),
+                  (None, 6, 'ICMP type (port-range-min) is missing'),
                   (300, 1, 'Invalid value for ICMP type')]
         for pmin, pmax, msg in states:
             ex = self.assertRaises(