Get salt version from grains + fix state function name for groupinstall

nginx/map.jinja

@@ -22,7 +22,7 @@
     },
     'RedHat': {
         'apache_utils': 'httpd-tools',
-        'group_action': 'pkg.group_install',
+        'group_action': 'pkg.group_installed',
         'group_pkg': 'Development Tools',
         'libpcre_dev': 'pcre-devel',
         'libssl_dev': 'openssl-devel',

nginx/source.sls

@@ -65,7 +65,7 @@ nginx_user:
     - makedirs: True
 
 get-build-tools:
-{% if salt['pkg.version']('salt') < '2015.8.0' and grains['os_family'] == 'RedHat' %}
+{% if grains['saltversion'] < '2015.8.0' and grains['os_family'] == 'RedHat' %}
   module.run:
     - name: pkg.group_install
     - m_name: {{ nginx_map.group_pkg }}