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/etcd/tasks/sync_etcd_master_certs.yml

@@ -1,7 +1,7 @@
 ---
 
 - name: sync_etcd_master_certs | Create list of master certs needing creation
-  set_fact: 
+  set_fact:
     etcd_master_cert_list: >-
         {{ etcd_master_cert_list|default([]) +  [
         "admin-" + item + ".pem",
@@ -11,7 +11,7 @@
   run_once: true
 
 - include: ../../vault/tasks/shared/sync_file.yml
-  vars: 
+  vars:
     sync_file: "{{ item }}"
     sync_file_dir: "{{ etcd_cert_dir }}"
     sync_file_hosts: "{{ groups.etcd }}"