Implement synchronous haproxy driver methods

Methods deploy the actual haproxy process when called.
Includes a service that periodically runs to collect stats.

Partially-implements: blueprint lbaas-api-and-objmodel-improvement
Partially-implements: blueprint lbaas-refactor-haproxy-namespace-driver-to-new-driver-interface

Change-Id: I95655b37a7ca6ade1edf44ebdfb3bf271640c636
Co-authored-by: Brandon Logan <brandon.logan@rackspace.com>
Co-authored-by: Phillip Toohill <phillip.toohill@rackspace.com>
Implements managers for synchronous haproxy driver

LoadBalancer, Listener, Pool, Member, and HealthMonitor Managers
Manager instances added into driver.

Partially-implements: blueprint lbaas-api-and-objmodel-improvement
Partially-implements: blueprint lbaas-refactor-haproxy-namespace-driver-to-new-driver-interface

Change-Id: I87bc3190ebb8bb708d2bd83192f9b42a42ccd457
Co-authored-by: Brandon Logan <brandon.logan@rackspace.com>
Co-authored-by: Phillip Toohill <phillip.toohill@rackspace.com>