python-chess v0.28.1

Bugfixes:

* The minimum Python version is 3.5.3 (instead of 3.5.0).
* Fix `board.is_irreversible()` when capturing a rook that had castling rights.

Changes:

* `is_en_passant()`, `is_capture()`, `is_zeroing()`, `is_irreversible()`,
  `is_castling()`, `is_kingside_castling()` and `is_queenside_castling()`
  now consistently return `False` for null moves.
* Added `chess.engine.InfoDict` class with typed shorthands for common keys.
* Support `[Variant "3-check"]` (from chess.com PGNs).