Fix ssh key installation on Mac OS X

The username for the root account is still root,
even though it is named System Administrator.

common/init.sls

@@ -24,6 +24,6 @@ host-{{ hostname }}:
 {% for ssh_user in config.ssh_users %}
 sshkey-{{ ssh_user }}:
   ssh_auth.present:
-    - user: {{ config.root_user }}
+    - user: root
     - source: salt://{{ tpldir }}/ssh/{{ ssh_user }}.pub
 {% endfor %}

common/map.jinja

@@ -2,7 +2,6 @@
   set config = salt['grains.filter_by']({
       'defaults': {
         'servo_home': '/home/servo',
-        'root_user': 'root',
         'hosts': {
           'servo-master': '96.126.125.232',
           'servo-linux1': '66.228.48.56',
@@ -28,8 +27,7 @@
         ]
       },
       'Darwin': {
-        'servo_home': '/Users/servo',
-        'root_user': 'administrator'
+        'servo_home': '/Users/servo'
       }
     },
     base='defaults',