Fix access method

[Pierozi]

the Error class use public call on method Base::convert_object_to_array()

[lode]

I rather not make this method public as should only be used internally.
I've fixed it in #15 by letter the error object extend the base class anyway. This is just released as v1.1.1.

Thanks for the report!

[Pierozi]

Ok great, thanks you for this lib, lightest and helpful.

[lode]

You're welcome, great to hear it is useful!