Follows the same linting configuration that was implemented first in
tripleo-quickstart-extras which makes used of pre-commit tool for
managing all linters.
This also avoids problems where a new linter release may break our
gates because pre-commit always pins versions.
Removes ansible from requirements.txt as it needs to be listed only
in ansible-requirements.txt
Change-Id: Ia229d3d58763d743bd19ad9099d7907561f3c77f
Depends-On: https://review.openstack.org/#/c/626000/
8ac74a8177