Added asf.yaml configuration for the new website handling.

This patch will persist the .asf.yaml configuration for the new website
publishing mechanism (https://github.com/apache/mesos-site/pull/2).

This closes #399
diff --git a/site/config.rb b/site/config.rb
index 04bc7aa..01ea84a 100644
--- a/site/config.rb
+++ b/site/config.rb
@@ -59,3 +59,9 @@
 activate :directory_indexes
 activate :syntax
 activate :livereload
+
+page "asf.yaml", :layout => false
+
+after_build do
+  File.rename 'publish/asf.yaml', 'publish/.asf.yaml'
+end
diff --git a/site/source/asf.yaml.erb b/site/source/asf.yaml.erb
new file mode 100644
index 0000000..0735550
--- /dev/null
+++ b/site/source/asf.yaml.erb
@@ -0,0 +1,2 @@
+publish:
+  whoami: asf-site