Replace deprecated sudo_user with become_user

The ``sudo`` and ``sudo_user`` directives are replaced with ``become``
and ``become_user`` in Ansible 1.9.

roles/common/tasks/google_auth.yml

 - name: Generate a timed-based, no reuse, rate-limited (3 logins per 30 seconds) with one concurrently valid code for default user
   command: /usr/bin/google-authenticator -t -f -d --label="{{ main_user_name }}@{{ domain }}" --qr-mode=ANSI -r 3 -R 30 -w 1 --secret=/home/{{ main_user_name }}/.google_authenticator
            creates=/home/{{ main_user_name }}/.google_authenticator
-  sudo: yes
-  sudo_user: "{{ main_user_name }}"
+  become: yes
+  become_user: "{{ main_user_name }}"
   when: ansible_ssh_user != "vagrant"
 
 - name: Retrieve generated keys from server

site.yml

 
 - hosts: all
   user: deploy
-  sudo: True
+  become: True
   gather_facts: True
   vars_files:
     - vars/defaults.yml