bump atc
bump atc

Submodule src/github.com/concourse/atc 612524f..a5638ef:
  > only exclude current type for resource containers

Signed-off-by: Evan Short <5b1db704470d35a058f1f4a9e1a5a172a6ea69d3@pivotal.io>

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