Use Django forcetext for choices

Author: syrusakbary

graphene/contrib/django/converter.py

@@ -1,4 +1,5 @@
 from django.db import models
+from django.utils.encoding import force_text
 
 from ...core.classtypes.enum import Enum
 from ...core.types.custom_scalars import DateTime, JSONString
@@ -14,7 +15,7 @@
 
 def convert_choices(choices):
     for value, name in choices:
-        yield to_const(name), value
+        yield to_const(force_text(name)), value
 
 
 def convert_django_field_with_choices(field):

graphene/utils/str_converters.py

@@ -18,4 +18,4 @@ def to_snake_case(name):
 
 
 def to_const(string):
-    return re.sub('[\W|^]+', '_', string.format()).upper()
+    return re.sub('[\W|^]+', '_', string).upper()