0.15.0

Added

• Add tests for PHP 8.1 (memcached is excluded)
• Add GitHub action for Release process
• Add CHANGELOG.md

Changed

• Remove composer.lock file
• Use BouncerException for some specific errors

Fixed

• Fix auto-prepend script: set debug_mode and display_errors values before bouncer init
• Fix gregwar/captcha for PHP 8.1
• Fix BouncerException arguments in set_error_handler method