Pconf

New features:
- Added support for Python 3.12
- Removed support for EoL Python versions: 3.6, 3.7

New features:
- Added support for Python 3.11
- Updated [deepmerge](https://pypi.org/project/deepmerge) to version 1.1.0

New features:
- Added support for Python 3.10
- Updated [deepmerge](https://pypi.org/project/deepmerge) to version 1.0.1

New features:
* Added support for Python 3.9
* Removed support for Python 2.7 and 3.5

Fixes:
* Fix an issue where calling `get()` multiple times would return the configuration in reverse order

Fixes:
* Updated pyyaml to [5.3.1](https://github.com/yaml/pyyaml/releases/tag/5.3.1), resolving [CVE-2020-1747](https://snyk.io/vuln/SNYK-PYTHON-PYYAML-559098) - arbitrary code execution