Automatically set up passwordless sudo for deploy user.

Closes #343.

README.md

     chmod 400 /home/deploy/.ssh/authorized_keys
     chown deploy:deploy /home/deploy -R
 
-This account should be set up for passwordless sudo. Use `visudo` and add this line:
-
-    deploy  ALL=(ALL) NOPASSWD: ALL
+Your new account will be automatically set up for passwordless `sudo`.
 
 ### 4. Configure your installation
 

roles/common/tasks/users.yml

 - name: Create main user account
   user: name={{ main_user_name }} state=present shell={{ main_user_shell }} groups=sudo,fuse
+
+- name: Give main user account sudo power
+  template: src=roles/common/templates/sudoers.j2 dest=/etc/sudoers.d/sudoers owner=root group=root mode=0440 validate='visudo -cf %s'

roles/common/templates/sudoers.j2

++{{ main_user_name }} ALL=(ALL) NOPASSWD: ALL