Skipped ipv6 test on Travis, because Travis no longer supports this.

We skip it when the TRAVIS environment variable is set.
So locally we still run it.

CHANGES.rst

@@ -11,6 +11,8 @@ http://docs.zope.org/zope2/
 Bugs Fixed
 ++++++++++
 
+- Skipped ipv6 test on Travis, because Travis no longer supports this.
+
 - LP #789863:  Ensure that Request objects cannot be published / traversed
   directly via a URL.
 

src/ZServer/tests/test_config.py

@@ -134,6 +134,8 @@ class ZServerConfigurationTestCase(BaseTest, WarningInterceptor):
         self.assertEqual(server.port, 9381)
         server.close()
 
+    @unittest.skipIf(os.environ.get('TRAVIS'),
+                     'ipv6 is not available on Travis anymore')
     def test_http_over_ipv6(self):
         factory = self.load_factory("""\
             <http-server>
@@ -149,7 +151,7 @@ class ZServerConfigurationTestCase(BaseTest, WarningInterceptor):
         self.assertEqual(server.ip, '::1')
         self.assertEqual(server.port, 9381)
         server.close()
-    
+
     def test_http_factory_defaulthost(self):
         factory = self.load_factory("""\
             <http-server>