wglass/lighthouse

0.10.0
~~~~~~

* Update nomenclature: "balancer" is now "coordinator", as it is a better fit
  with what the class actually does.

* The redis check is moved to an "extra".  To install it the bracket syntax must
  be used (i.e. "pip install lighthouse[redis]").

* New TCPCheck health check for services that expose a TCP command for health
  checks, such as redis and zookeeper.

* A service that has no valid health checks no longer defaults to unavailable.
  Each round of checks fires a warning about having no checks but still reports
  as available.