Fix the test VM which was not listening anywhere

The test configuration was turning off the SSL listener, but since there
was no TCP address listener given in the test configuration RabbitMQ was
running without any listening address.

Vagrantfile

@@ -8,6 +8,7 @@ Vagrant.configure('2') do |config|
     ansible.extra_vars = {
       rabbitmq_vhost_definitions: ['sensu'],
       rabbitmq_ssl: false,
+      rabbitmq_conf_tcp_listeners_address: '0.0.0.0',
       rabbitmq_users_definitions: [
         {
           vhost: 'sensu',