Add 619/639 to Changelog

Changelog.md

@@ -5,6 +5,7 @@
 - Bug #594: Fix may_<trigger> always returning false for internal transitions (thanks @a-schade)
 - PR #592: Pass investigated transition to `EventData` context in 'may' check (thanks @msclock)
 - PR #634: Improve the handling of diagrams when working with parallel states, especially when using the show_roi option (thanks @seanxlliu)
+- Bug #619/#639: `Exception` is not broad enough and does not catch `asyncio.CancelledError` or `KeyboardInterrupt`; use `BaseException` instead (thanks @e0lithic and @ofacklam)
 - '_anchor' suffix has been removed for (py)graphviz cluster node anchors
 - local testing switched from [tox](https://github.com/tox-dev/tox) to [nox](https://github.com/wntrblm/nox)
 - PR #633: Remove surrounding whitespace from docstrings (thanks @artofhuman)