Use boulder for hostname during ServerSpec testing

Author: ramereth

test/integration/default/serverspec/server_spec.rb

@@ -2,6 +2,6 @@
 
 set :backend, :exec
 
-describe command('curl http://127.0.0.1:4000/directory') do
+describe command('curl http://boulder:4000/directory') do
   its(:stdout) { should match(%r{"new-cert": "http://127.0.0.1:4000/acme/new-cert"}) }
 end