fix deprecation warnings in python3.8 and above

[Rogalek]

Hello,

I want to fix deprecation warnings in pyramid_celery, which cause my project an error:

/usr/local/lib/python3.8/site-packages/pyramid_celery/loaders.py:99: in __init__
    self.parser = self.ConfigParser()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
self = <configparser.SafeConfigParser object at 0x7fada6845580>, args = (), kwargs = {}
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
>       warnings.warn(
            "The SafeConfigParser class has been renamed to ConfigParser "
            "in Python 3.2. This alias will be removed in future versions."
            " Use ConfigParser directly instead.",
            DeprecationWarning, stacklevel=2
        )
E       DeprecationWarning: The SafeConfigParser class has been renamed to ConfigParser in Python 3.2. This alias will be removed in future versions. Use ConfigParser directly instead.

Also, I have found two minor things to change.

PEP 8: E124 closing bracket does not match visual indentation in your setup.py file

  /home/rogal/Documents/repo/pyramid_celery/venv/lib/python3.8/site-packages/_pytest/config/__init__.py:1183: PytestDeprecationWarning: The --strict option is deprecated, use --strict-markers instead.
    self.issue_config_time_warning(
-- Docs: https://docs.pytest.org/en/stable/warnings.html

Run all your tests by tox:

______________________________________________________________________________________________________________________________________________________________________________ summary ______________________________________________________________________________________________________________________________________________________________________________
  py36: commands succeeded
  py37: commands succeeded
  py38: commands succeeded
  py39: commands succeeded
  pypy3: commands succeeded
  flake8: commands succeeded
  celery4: commands succeeded
  celery5: commands succeeded
  congratulations :)

[coveralls]

Coverage remained the same at 95.031% when pulling d062aee5b266ab73ac5d1444c9db507992c33316 on Rogalek:fix_deprecation_warnings_py3.8 into cf8aa80980e42f7235ad361874d3c35e19963b60 on sontek:master.

[fmigneault]

@sontek Is it possible to include this fix and provide a new patch release? With Python 3.12, this is not a warning anymore, but an error:

    import pyramid_celery
  File "/opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/pyramid_celery/__init__.py", line 6, in <module>
    from pyramid_celery.loaders import INILoader
  File "/opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/pyramid_celery/loaders.py", line 94, in <module>
    class INILoader(celery.loaders.base.BaseLoader):
  File "/opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/pyramid_celery/loaders.py", line 95, in INILoader
    ConfigParser = configparser.SafeConfigParser
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'configparser' has no attribute 'SafeConfigParser'. Did you mean: 'RawConfigParser'?

See https://docs.python.org/3/whatsnew/3.12.html#configparser