Install watchtower

Also move file masks to config so they're consistent

ansible/roles/docker/tasks/netdata.yml

@@ -3,7 +3,7 @@
     path: '/opt/netdata'
     state: directory
     owner: "{{ docker_user.name }}"
-    mode: 0755
+    mode: "{{ docker_compose_directory_mask }}"
   become: true
   become_user: root
 
@@ -11,15 +11,13 @@
   template:
     src: files/netdata/docker-compose.yml
     dest: "/opt/netdata/docker-compose.yml"
-    mode: 0644
+    mode: "{{ docker_compose_file_mask }}"
     owner: "{{ docker_user.name }}"
-    backup: true
-    trim_blocks: false
   register: compose_file
   become: true
   become_user: root
 
-- name: Cycle container
+- name: Cycle netdata container
   docker_compose:
     project_src: /opt/netdata
     pull: true