There have been a handful of changes recently to fix stylistic bugs
in the unit tests (example: If41a7). The changes themselves were fine,
but there are two problems:
1) The stylistic changes they made were not listed in HACKING.rst
2) They were one-time changes; the rules that were violated will
continue to be violated.
This change updates HACKING.rst to include a few of the stylistic
rules that have been fixed recently, and adds checks to ensure that
they will be enforced going forward. This is based on nova's hacking
checks.
Change-Id: Ic115342605c472f3a5d255aa570ecb60175ca087
3994eeb862