Format code base with black

https://black.readthedocs.io/en/stable/

JIRA: COMPOSE-4086
Signed-off-by: Haibo Lin <hlin@redhat.com>

tox.ini

@@ -1,15 +1,15 @@
 [flake8]
 exclude = doc/*,*.pyc,*.py~,*.in,*.spec,*.sh,*.rst,setup.py
 filename = *.py
+max-line-length = 88
 
 # E402: module level import not at top of file
-# E501: line too long
 # H301: one import per line
 # H306: imports not in alphabetical order
 # E226: missing whitespace around arithmetic operator
 # W503: line break occured before a binary operator
 # E203: whitespace before ':'
-ignore = E501,E402,H301,H306,E226,W503,E203
+ignore = E402,H301,H306,E226,W503,E203
 
 [run]
 omit = tests/*