- modified `create_radius_account()` method to make Tunnel Type and Medium optional parameters, contributed by @mreho
- added `advanced_adopt_device()` method for more advanced adoption capabilities, contributed by @Sarrus
- refactored several code sections
- updated connection test script
- minor syntax improvements based on Scrutinizer CI feedback
- added support for PATCH requests (for future use)
- completed updating method/function comments to PHPDoc format (PSR-5)