lint: Configure Black.
MODIFY
pyproject.toml
pyproject.toml
+[tool.black]
+line-length = 100
+target-version = ["py36"]
+
[tool.isort]
src_paths = ["tools", "zulip", "zulip_bots", "zulip_botserver"]
profile = "black"

MODIFY
requirements.txt
requirements.txt
crayons
twine
coverage>=4.4.1
+black
isort
flake8
mock

lint: Configure Black.