The RPM file that's provided by upstream can be used for SUSE
distributions as well. Moreover we simplify the playbook to use
the 'package' module to install packages across different distros.
Link: https://github.com/rkt/rkt/pull/3904
* Adding yaml linter to ci check
* Minor linting fixes from yamllint
* Changing CI to install python pkgs from requirements.txt
- adding in a secondary requirements.txt for tests
- moving yamllint to tests requirements
