This patch is mainly porting from nova repository:
Adds:
1.tools/flake8wrap.sh
Will let developer use 'tox -epep8 -- -HEAD' to testing changes files
2.tools/pretty_tox.sh
Give pretty test trace when doing unit/functional testing.
Change-Id: Icedb4ed8b50532531e18784a1584fe63c5a9e017