bump testflight
bump testflight

Submodule src/github.com/concourse/testflight 615c3b2..62721ca:
  > configure an image

concourse/concourse,cjcjameson/concourse,cjcjameson/concourse,concourse/concourse,cjcjameson/concourse,concourse/concourse,concourse/concourse,concourse/concourse