Deploy issue ansible 1.9.4 composer not found

Thank you Phil! That may have been the missing ingredient because it’s now installing but I ran into a seperate issue:

stderr: Error: YIKES! It looks like you're running this as root. You probably meant to run this as the user that your WordPress install exists under.

but does this create a user for me? It says: If you’d like to run it as the user that this site is under, you can run the following to become the respective user: sudo -u USER -i – wp

but if change web_user: to any invented name it doesn’t work.

# Documentation: https://roots.io/trellis/docs/ssh-keys/
admin_user: goltastico

users:
  - name: "{{ web_user }}"
    groups:
      - "{{ web_group }}"
    keys:
      - "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
      # - https://github.com/codingideas.keys
  - name: "{{ admin_user }}"
    groups:
      - sudo
    keys:
      - "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
      # - https://github.com/codingideas.keys

web_user: root
web_group: www-data
web_sudoers:
  - "/usr/sbin/service hhvm *"
  - "/usr/sbin/service php5-fpm *"