Keystone's tox.ini contains an "ignore" entry for H405 violations:
multi line docstring summary not separated with an empty line.
All violations of H405 should be fixed so that H405 can be removed
from the ignore list.
Change-Id: I1b2aae0cabc20909cf3b0a405d5e31c5d91148b2
Closes-Bug: #1482773