bump go-concourse
bump go-concourse

[finishes #108151468]

Submodule src/github.com/concourse/go-concourse affe29d..ec9414f:
  > update request types to use http package types

Signed-off-by: Toby Rumans <516e7840355d33b790e9dc5c111fe7c7c270a08f@pivotal.io>
Signed-off-by: Alex Suraci <a8053324ea51f0cc533cfe7b17f8bee3c920919f@pivotal.io>

cjcjameson/concourse,concourse/concourse,zachgersh/concourse,concourse/concourse,concourse/concourse,cjcjameson/concourse,cjcjameson/concourse,longnguyen11288/concourse,zachgersh/concourse,concourse/concourse,longnguyen11288/concourse,longnguyen11288/concourse,concourse/concourse,zachgersh/concourse