Send INT to worker to stop accepting new tasks
Send INT to worker to stop accepting new tasks

[#112936411](https://www.pivotaltracker.com/story/show/112936411)

Signed-off-by: Kam Leung <bbd6ea552864be24bc8b0a608253fbbecfbc9c10@pivotal.io>

barthy1/bosh,barthy1/bosh,barthy1/bosh,barthy1/bosh