Do not sync salt-cloud provided default configuration by default

As discussed in PR#305, these are defaults that even if they are
configurable as probably not suited to a majority of users and causes
delete/add output on highstate of user of the formula choses to use
the same file name.

salt/cloud.sls

     - source: {{ salt_settings.cloud.template_sources[cloud_section] }}
     - template: jinja
     - makedirs: True
+    - exclude_pat: _*
 
 {% for filename in salt['pillar.get']("salt:cloud:" ~ cloud_section, {}).keys() %}
 /etc/salt/cloud.{{ cloud_section }}.d/{{ filename }}: