New features:
- Nested ConversationHandlers (#1512).
Minor changes, CI improvments or bug fixes:
- Fix CI failures due to non-backward compat attrs depndency (#1540).
- travis.yaml: TEST_OFFICIAL removed from allowed_failures.
- Fix typos in examples (#1537).
- Fix Bot.to_dict to use proper first_name (#1525).
- Refactor
test_commandhandler.py(#1408). - Add Python 3.8 (RC version) to Travis testing matrix (#1543).
- test_bot.py: Add to_dict test (#1544).
- Flake config moved into setup.cfg (#1546).