unicorn 0.8.4

This release allows graceful degradation in case a user is using a
status code not defined by Rack::Utils::HTTP_STATUS_CODES.  A patch has
been submitted[1] upstream to Rack but this issue may still affect users
of yet-to-be-standardized status codes.

Eric Wong (2):
      http_response: pass through unknown status codes
      unicorn 0.8.4

[1] - http://rack.lighthouseapp.com/projects/22435-rack/tickets/70