Add 'meta' column to fuel2 network-group show output

Change-Id: Ifa73dfbc8bd82d6d694907fa722c7cb5334bfcbb
Closes-Bug: #1482520

fuelclient/commands/network_group.py

@@ -77,11 +77,10 @@ class NetworkGroupList(NetworkGroupMixin, base.BaseListCommand):
     )
 
 
-# TODO(asaprykin): Include metadata field to the output
 class NetworkGroupShow(NetworkGroupMixin, base.BaseShowCommand):
     """Show network group."""
 
-    columns = NetworkGroupList.columns
+    columns = NetworkGroupList.columns + ('meta',)
 
 
 class NetworkGroupCreate(NetworkGroupMixin, base.BaseShowCommand):

fuelclient/tests/v2/unit/lib/test_network_group.py

@@ -39,15 +39,26 @@ class TestNetworkGroupFacade(test_api.BaseLibTest):
         self.assertTrue(matcher.called)
 
     def test_network_group_show(self):
+        expected_fields_names = (
+            'id',
+            'name',
+            'vlan_start',
+            'cidr',
+            'gateway',
+            'group_id',
+            'meta'
+        )
         net_id = 42
         uri = self.get_object_uri(self.res_uri, net_id)
 
         matcher = self.m_request.get(
             uri, json=self.fake_network_group)
 
-        self.client.get_by_id(net_id)
+        data = self.client.get_by_id(net_id)
 
         self.assertTrue(matcher.called)
+        self.assertTrue(all(f in data for f
+                            in expected_fields_names))
 
     def test_network_group_create(self):
         fake_ng = self.fake_network_group