Flake8 currently ignores the following errors:
H237: module is removed in python3
H238: old style class declaration
Enable them for python2/3 compatibility
Change-Id: I4dd66c8ab388119b4abab83fda48a89e108f7821
Story: 2004515
Task: 29303
Signed-off-by: Eric Barrett <eric.barrett@windriver.com>