Using file module instead of chmod (Fixes #326)

New pull request to fix following warning. 

[WARNING]: Consider using file module with mode rather than running chmod

roles/iiab-admin/tasks/admin-user.yml

@@ -33,7 +33,8 @@
 #        backup=yes
 
 - name: edit the sudoers file--first make it editable
-  shell: chmod 0640 /etc/sudoers
+  file: path=/etc/sudoers
+        mode=0640
 
 - name: have sudo log all commands it handles
   lineinfile: regexp=logfile
@@ -52,4 +53,5 @@
               dest=/etc/sudoers
 
 - name: end editing the sudoers file-- protect it again
-  shell: chmod 0440 /etc/sudoers
+  file: path=/etc/sudoers
+        mode=0440