Set up SpamAssassin

Scan incoming and outgoing email for spam. Use a local Unbound for DNS,
so we don't run into blocks for RBL queries.

cookbooks/unbound/metadata.rb

@@ -0,0 +1,13 @@
+name             'unbound'
+maintainer       'Sous Chefs'
+maintainer_email 'help@sous-chefs.org'
+license          'Apache-2.0'
+description      'Manages unbound DNS resolver'
+version          '3.0.2'
+issues_url       'https://github.com/sous-chefs/unbound/issues'
+source_url       'https://github.com/sous-chefs/unbound'
+chef_version     '>= 16'
+
+%w(debian ubuntu centos redhat scientific oracle amazon).each do |os|
+  supports os
+end