Fixed logic bug

[feirouu]

No description provided.

[feirouu]

I defined an interface.

class MutationResponse(Interface):
    code = Int(required=True, default_value=200)
    success = Boolean(required=True, default_value=True)
    message = String(required=True, default_value="something...")

class DoSomething(Mutation):
    class Meta:
        interfaces = (MutationResponse,)
    def mutate(self, info):
        return DoSomething()

print(DoSomething._meta.fields)

# output
OrderedDict()

# expected output
# {'code': <graphene.types.field.Field object at 0x112185970>, 'success': <graphene.types.field.Field object at 0x1121859a0>, 'message': <graphene.types.field.Field object at 0x112185a90>}