fixed deprecation warnings regarding bare variables

roles/kubernetes/master/tasks/main.yml

@@ -45,7 +45,7 @@
 - meta: flush_handlers
 
 - include: start.yml
-  with_items: groups['kube-master']
+  with_items: "{{ groups['kube-master'] }}"
   when: "{{ hostvars[item].inventory_hostname == inventory_hostname }}"
 
 # Create kube-system namespace

roles/kubernetes/preinstall/tasks/etchosts.yml

@@ -8,7 +8,7 @@
     create: yes
     backup: yes
   when: hostvars[item].ansible_default_ipv4.address is defined
-  with_items: groups['all']
+  with_items: "{{ groups['all'] }}"
 
 - name: Hosts | populate kubernetes loadbalancer address into hosts file
   lineinfile:

roles/kubernetes/secrets/tasks/gen_certs.yml

@@ -48,4 +48,4 @@
   file:
     path: "{{ item }}"
     mode: 0600
-  with_items: keyfiles.stdout_lines
+  with_items: "{{ keyfiles.stdout_lines }}"