Fix build failures

This PR includes patches to fix build failures.

* Additional apt-get update to fix key errors found
   This is a possible fix on failures happening on installing packages because of package authentication errors.  (possible fix for the issue #211
* Haproxy node should know all services to be configured
   This is a possible fix for issue #213
* Haproxy backend service validation
   This patch add haproxy backend validation using socat to collect haproxy stats
    and thus checks each backend server are there in haproxy configuration and
    optionally verifiy individual backend service state.
* Sort the IP addresses to configure haproxy
   This will avoid unnecessary haproxy reconfiguration and restart on every puppet run.
why not just rerun the whole script if is fails?