Version check logic changed

Author: arunsureshkumar

graphene_mongo/converter.py

@@ -425,7 +425,7 @@ def dynamic_type():
     return graphene.Dynamic(dynamic_type)
 
 
-if sys.version_info[0] > 3:
+if sys.version_info[0] >= 3:
     @convert_mongoengine_field.register(mongoengine.EnumField)
     def convert_field_to_enum(field, registry=None):
         return graphene.Field(graphene.Enum.from_enum(field._enum_cls),