Remove unused kubelet user from salt.

Fixes #1512.

Cluster creation and validation succeeds with this change.

cluster/saltbase/salt/kubelet/init.sls

@@ -51,19 +51,6 @@
     - makedirs: true
 
 kubelet:
-  group.present:
-    - system: True
-  user.present:
-    - system: True
-    - gid_from_name: True
-    - shell: /sbin/nologin
-    - home: /var/lib/kubelet
-{% if grains['os_family'] != 'RedHat' %}    
-    - groups:
-      - docker
-{% endif %}      
-    - require:
-      - group: kubelet
   service.running:
     - enable: True
     - watch: