Renamed conn to session in the README. The example starts off by creating
a session, but then used a "conn" variable that seemingly comes from nowhere.
Added the retries and retryDelay connection options. By default, retries is 0
which preserves the existing behavior. However, setting retries to a value
either greater than 0, or to -1 (for unlimited retries), will result in the
driver trying to re-establish a failed connections. retryDelays specify the
delay between retries (defaults to 1 milliseconds).

Currently, a failure is detected when writing to the underlying connection
fails. This appears to handle the most common cases.