Support links in v2 files

Signed-off-by: Aanand Prasad <aanand.prasad@gmail.com>

tests/unit/service_test.py

@@ -536,14 +536,6 @@ class ServiceTest(unittest.TestCase):
             ports=["127.0.0.1:1000-2000:2000-3000"])
         self.assertEqual(service.specifies_host_port(), True)
 
-    def test_get_links_with_networking(self):
-        service = Service(
-            'foo',
-            image='foo',
-            links=[(Service('one'), 'one')],
-            use_networking=True)
-        self.assertEqual(service._get_links(link_to_self=True), [])
-
     def test_image_name_from_config(self):
         image_name = 'example/web:latest'
         service = Service('foo', image=image_name)