Version 13.6

Released 2021-06-06

New Features:

• Arbitrary callback_data (#1844)
• Add ContextTypes & BasePersistence.refresh_user/chat/bot_data (#2262)
• Add Filters.attachment (#2528)
• Add pattern Argument to ChosenInlineResultHandler (#2517)

Major Changes:

• Add __slots__ (#2345)

Minor changes, CI improvements, Doc fixes and Type hinting:

• Doc Fixes (#2495, #2510)
• Add max_connections Parameter to Updater.start_webhook (#2547)
• Fix for Promise.done_callback (#2544)
• Improve Code Quality (#2536, #2454)
• Increase Test Coverage of CallbackQueryHandler (#2520)
• Stabilize CI (#2522, #2537, #2541)
• Fix send_phone_number_to_provider argument for Bot.send_invoice (#2527)
• Handle Classes as Input for BasePersistence.replace/insert_bot (#2523)
• Bump Tornado Version and Remove Workaround from #2067 (#2494)