add pain text ip address field to Sliver form
diff --git a/plstackapi/core/serializers.py b/plstackapi/core/serializers.py
index 5e077dc..2b70357 100644
--- a/plstackapi/core/serializers.py
+++ b/plstackapi/core/serializers.py
@@ -166,6 +166,7 @@
         fields = ('id',
                   'instance_id',
                   'name',
+                  'ip',
                   'flavor',
                   'image',
                   'key',