Python 3.10 compatibility

[chStaiger]

The current version is unfortunately no longer compatible with python3.10.X

ImportError: cannot import name 'Iterable' from 'collections'

File /opt/homebrew/lib/python3.10/site-packages/specio/core/__init__.py:6, in <module>
      1 """ This subpackage provides the core functionality of specio
      2 (everything but the plugins).
      3 """
      5 from .util import Spectrum, Dict
----> 6 from .format import Format, FormatManager
      7 from .exceptions import CannotReadSpectraError
      8 from .request import Request

File /opt/homebrew/lib/python3.10/site-packages/specio/core/format.py:10, in <module>
      7 from __future__ import print_function
      9 import os
---> 10 from collections import Iterable