v2.1-beta2

Added

• Improve logger display in-WordPress.
• Adds ai_logger_handlers and ai_logger_processors filters to allow Monolog
  handlers and processors to be filtered.
• Adds ai_logger()->to_post() and ai_logger()->to_term() methods for easily
  creating a logger with a post/term handler

Changed

• Implements Psr\Log\LoggerInterface on the AI_Logger\AI_Logger class to
  allow the logger to support DI against the logger interface.
• Moved to GitHub actions for continuous integration.