manage-haproxy role should support a directory of configuration files

[oybed]

As-is, the manage-haproxy role includes all configuration in one file. This works, but may be a bit hard to manage at times. The role should be updated to support using multiple files to manage the frontend/backend configuration. As a result, the configuration structure would look something like:

/etc/haproxy/
  |-haproxy.cfg
  |-conf.d
    |-frontend-one.example.com.cfg
    |-frontend-two.example.com.cfg
    |-backend-example.com.cfg

In order for this work, an extra -f /etc/haproxy/conf.d needs to be added to the haproxy options in /etc/sysconfig/haproxy