Ansible 2.3 support

- Fix when clauses in various places
- Update requirements.txt
- Fix README.md

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

roles/kubernetes/secrets/tasks/sync_kube_master_certs.yml

@@ -6,7 +6,7 @@
   with_items: "{{ groups['kube-master'] }}"
 
 - include: ../../../vault/tasks/shared/sync_file.yml
-  vars: 
+  vars:
     sync_file: "{{ item }}"
     sync_file_dir: "{{ kube_cert_dir }}"
     sync_file_group: "{{ kube_cert_group }}"
@@ -38,7 +38,7 @@
   set_fact:
     kube_api_certs_needed: "{{ item.path }}"
   with_items: "{{ sync_file_results|d([]) }}"
-  when: "{{ item.no_srcs }}"
+  when: item.no_srcs
 
 - name: sync_kube_master_certs | Unset sync_file_results after apiserver cert
   set_fact:
@@ -46,7 +46,7 @@
 
 
 - include: ../../../vault/tasks/shared/sync_file.yml
-  vars: 
+  vars:
     sync_file: ca.pem
     sync_file_dir: "{{ kube_cert_dir }}"
     sync_file_group: "{{ kube_cert_group }}"