bump atc
bump atc

Submodule src/github.com/concourse/atc 61b66ec..df7b3e3:
  > remove focus

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