Adds pip installation of python deps in deb package install

Adds postinst script
Adds Makefile (there is an issue when using postinst with tox)
Adds stdeb.cfg declaring binary dependencies
Reenables flake8 in tox
Removes consumer timeout that should have never been there
Readds group_id in kafka consumer

Signed-off-by: Benjamin Diaz <bdiaz@whitestack.com>
Change-Id: Ied0cb6135aee5f08cfd36c9cbaafa4c174b7434f