Do not vendor cookbooks using Berkshelf anymore

Instead, use the Berkshelf support in knife-solo and the
vagrant-berkshelf plugin on Vagrant

cookbooks/selinux/libraries/selinux_service_helpers.rb

@@ -1,13 +0,0 @@
-module SELinuxServiceHelpers
-  def self.selinux_bool(bool)
-    if ['on', 'true', '1', true, 1].include? bool
-      'on'
-    elsif ['off', 'false', '0', false, 0].include? bool
-      'off'
-    else
-      Chef::Log.warn "Not a valid boolean value: #{bool}"
-      nil
-    end
-  end
-end
-