Sprockets-postgres

Previous releases would include the database password in log messages when running in debug mode. This release replaces the password when logging connection DSNs with a fixed ***** string.

- Implements a change in sprockets_postgres.PostgresConnector to only handle `psycopg2.OperationalError` and `asyncio.TimeoutError` so that other exceptions are not swallowed as connection issues when using the context manager.
- Logs a warning when a QueryResult object is being built and a `psycopg2.ProgrammingException` is raise with a `pgcode` value which should never happen.
- Adds an optional `sprockets_postgres.StatusRequestHandler` as a quick implementation of a RequestHandler for API health-checking.

Fix a bug in statsd metric submission where the order of the arguments being passed in was incorrect.

Creating asyncio objects in `tornado.web.Application.__init__` causes issues with multi-process application creation when initializing the HTTP server.

Only change is the DEBUG log entry for the URL being connected to

This update adds rediscovery of SRV records when a connection is interrupted.
In addition it changes SRV behavior to include all hosts returned in SRV records, in priority and weight order as part of the computed Postgres URL.