explicitly run inigo as a privileged build

(now required by concourse v0.16.0+)
bump inigo

Submodule src/github.com/cloudfoundry-incubator/inigo 670dedd..66c4388:
  > bump default timeout to 1 minute, + cleanup
  > expect loggregator to be up; don't silently fail
fix commit-with-submodule-log with special chars