bump atc
bump atc

[finishes #94972484]

Submodule src/github.com/concourse/atc a6fd7e8..b1732f3:
  > change pending animation to match color of pending job

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

Amit-PivotalLabs/concourse,zachgersh/concourse,longnguyen11288/concourse,squeedee/concourse,beni55/concourse,CloudCredo/concourse,jbayer/concourse,zachgersh/concourse,longnguyen11288/concourse,longnguyen11288/concourse,CloudCredo/concourse,concourse/concourse,sedouard/concourse,Amit-PivotalLabs/concourse,cjcjameson/concourse,CloudCredo/concourse,concourse/concourse,cjcjameson/concourse,zachgersh/concourse,sedouard/concourse,beni55/concourse,jbayer/concourse,squeedee/concourse,holgero/concourse,holgero/concourse,sedouard/concourse,jbayer/concourse,concourse/concourse,concourse/concourse,squeedee/concourse,holgero/concourse,Amit-PivotalLabs/concourse,cjcjameson/concourse,concourse/concourse,beni55/concourse