Haproxy to use consul for service discovery

Setup Haproxy to use consul for service discovery.
Earlier it was using etcd.

Also, update the tests.

1. Have the openrc file used for testing use the
   lb.keystone.service.consul address.

2. Be way more aggressive about the test used to
   validate a functional haproxy instance. Ensure
   that it is forwarding traffic to both keystone
   as well as glance explicitly.