add tests to verify the expected mysql error codes are returned
add tests to verify the expected mysql error codes are returned

Signed-off-by: Michael Demmer <4b836671cce77b1b2fbe63e5b2a1661879d8af44@slack-corp.com>

dcadevil/vitess,HubSpot/vitess,mahak/vitess,tirsen/vitess,mattharden/vitess,enisoc/vitess,mattharden/vitess,enisoc/vitess,davygeek/vitess,tinyspeck/vitess,tinyspeck/vitess,mattharden/vitess,tirsen/vitess,mahak/vitess,HubSpot/vitess,mattharden/vitess,davygeek/vitess,enisoc/vitess,vitessio/vitess,tirsen/vitess,dcadevil/vitess,davygeek/vitess,alainjobart/vitess,mattharden/vitess,tinyspeck/vitess,mahak/vitess,tinyspeck/vitess,vitessio/vitess,mattharden/vitess,HubSpot/vitess,davygeek/vitess,tinyspeck/vitess,enisoc/vitess,vitessio/vitess,tinyspeck/vitess,dcadevil/vitess,dcadevil/vitess,mattharden/vitess,alainjobart/vitess,alainjobart/vitess,mahak/vitess,vitessio/vitess,mahak/vitess,tirsen/vitess,HubSpot/vitess,mahak/vitess,enisoc/vitess,dcadevil/vitess,HubSpot/vitess,vitessio/vitess,alainjobart/vitess,mahak/vitess,alainjobart/vitess,tirsen/vitess,davygeek/vitess,davygeek/vitess,alainjobart/vitess,vitessio/vitess,mattharden/vitess,enisoc/vitess,HubSpot/vitess,dcadevil/vitess,mattharden/vitess,tirsen/vitess,davygeek/vitess,alainjobart/vitess,enisoc/vitess,mahak/vitess,dcadevil/vitess,HubSpot/vitess,HubSpot/vitess,tirsen/vitess,vitessio/vitess,mattharden/vitess,tirsen/vitess,tirsen/vitess,tinyspeck/vitess,alainjobart/vitess,vitessio/vitess