Update fixtures for the iptrunk network

Use custom method in faker to avoid random allocation of /32 addresses as network addresses

test/fixtures.py

@@ -235,8 +235,8 @@ def iptrunk_subscription_factory(iptrunk_side_subscription_factory, faker):
         geant_s_sid = geant_s_sid or faker.geant_sid()
         iptrunk_description = iptrunk_description or faker.sentence()
         iptrunk_isis_metric = iptrunk_isis_metric or faker.pyint()
-        iptrunk_ipv4_network = iptrunk_ipv4_network or faker.ipv4(network=True)
-        iptrunk_ipv6_network = iptrunk_ipv6_network or faker.ipv6(network=True)
+        iptrunk_ipv4_network = iptrunk_ipv4_network or faker.ipv4_network(max_subnet=31)
+        iptrunk_ipv6_network = iptrunk_ipv6_network or faker.ipv6_network(max_subnet=126)
         iptrunk_minimum_links = 1
         iptrunk_side_a = iptrunk_side_subscription_factory()
         iptrunk_side_b = iptrunk_side_subscription_factory()