Adding yamllinter to ci steps (#1556)

* 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

roles/docker/handlers/main.yml

@@ -8,7 +8,7 @@
     - Docker | pause while Docker restarts
     - Docker | wait for docker
 
-- name : Docker | reload systemd
+- name: Docker | reload systemd
   shell: systemctl daemon-reload
 
 - name: Docker | reload docker.socket