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/install_docker.yml

@@ -1,5 +1,5 @@
 ---
-#Plan A: no docker-py deps
+# Plan A: no docker-py deps
 - name: Install | Copy etcdctl binary from docker container
   command: sh -c "{{ docker_bin_dir }}/docker rm -f etcdctl-binarycopy;
            {{ docker_bin_dir }}/docker create --name etcdctl-binarycopy {{ etcd_image_repo }}:{{ etcd_image_tag }} &&
@@ -12,21 +12,21 @@
   delay: "{{ retry_stagger | random + 3 }}"
   changed_when: false
 
-#Plan B: looks nicer, but requires docker-py on all hosts:
-#- name: Install | Set up etcd-binarycopy container
-#  docker:
-#    name: etcd-binarycopy
-#    state: present
-#    image: "{{ etcd_image_repo }}:{{ etcd_image_tag }}"
-#  when: etcd_deployment_type == "docker"
+# Plan B: looks nicer, but requires docker-py on all hosts:
+# - name: Install | Set up etcd-binarycopy container
+#   docker:
+#     name: etcd-binarycopy
+#     state: present
+#     image: "{{ etcd_image_repo }}:{{ etcd_image_tag }}"
+#   when: etcd_deployment_type == "docker"
 #
-#- name: Install | Copy etcdctl from etcd-binarycopy container
-#  command: /usr/bin/docker cp "etcd-binarycopy:{{ etcd_container_bin_dir }}etcdctl" "{{ bin_dir }}/etcdctl"
-#  when: etcd_deployment_type == "docker"
+# - name: Install | Copy etcdctl from etcd-binarycopy container
+#   command: /usr/bin/docker cp "etcd-binarycopy:{{ etcd_container_bin_dir }}etcdctl" "{{ bin_dir }}/etcdctl"
+#   when: etcd_deployment_type == "docker"
 #
-#- name: Install | Clean up etcd-binarycopy container
-#  docker:
-#    name: etcd-binarycopy
-#    state: absent
-#    image: "{{ etcd_image_repo }}:{{ etcd_image_tag }}"
-#  when: etcd_deployment_type == "docker"
+# - name: Install | Clean up etcd-binarycopy container
+#   docker:
+#     name: etcd-binarycopy
+#     state: absent
+#     image: "{{ etcd_image_repo }}:{{ etcd_image_tag }}"
+#   when: etcd_deployment_type == "docker"