bump auction inigo gunk

Submodule src/github.com/cloudfoundry-incubator/auction 7ed3a9a..2af0c7a:
  > ignore closedChan [#79543220]
Submodule src/github.com/cloudfoundry-incubator/inigo 66c4388..732aa41:
  > ignore closedChan [#79543220]
Submodule src/github.com/cloudfoundry/gunk 91b64b6..dd2a403:
  > exit with error if natsConn closed unexpectedly