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/kubernetes-apps/efk/kibana/tasks/main.yml

@@ -1,6 +1,6 @@
 ---
 - name: "Kibana | Write Kibana deployment"
-  template: 
+  template:
     src: kibana-deployment.yml.j2
     dest: "{{ kube_config_dir }}/kibana-deployment.yaml"
   register: kibana_deployment_manifest
@@ -17,7 +17,7 @@
   run_once: true
 
 - name: "Kibana | Write Kibana service "
-  template: 
+  template:
     src: kibana-service.yml.j2
     dest: "{{ kube_config_dir }}/kibana-service.yaml"
   register: kibana_service_manifest