build group list for user

compile error

local:
    Data failed to compile:
----------
    Rendering SLS 'base:pscweb-test.vhost_users' failed: Jinja syntax error: expected token ':', got '}'; line 9

site_users.sls

#site_users.sls
{%for user,args in pillar['site_users'].iteritems() %}
{{ user }}:
  user.present:
    - home: {{ args['home'] }}
    - shell: /bin/false
    - gid_from_name: True

{% set group_list = {{ group_list }} + [ '{{ user }}' ] %}

{% endfor %}

cmstransport:
  user.present:
    - groups:
      - cis-webdev
      {{ group_list }}