* Add code to pull the latest supported versions of PostgreSQL from the
official RSS feed.
* TODO: Split rss parsing code into separate function for unit testing.
* TODO: Test/debug
* TODO: Add metrics to return how far behind the latest version the
current cluster is.
* Add a mode to test all metric queries
* Add a script to run query tests against different versions of
PostgeSQL
* Add Docker elements for query testing
* Switch to using a --config flag when specifying the config file
* Fix some metric queries
* Allow the agent address to be configured
* Allow the sslmode connection parameter to be configured
* Ensure the log directory exists with openrc
* Add a port setting to configure the port the agent listens on
* Switch to RealDictCursor
* Fix type for connection timeout
