add a post-deploy-script job

[drawsmcgraw]

I have a need to install some antivirus software but, due to the way the software behaves, I need to install it after all other Bosh jobs have completed. To me, I can take advantage of the post-deploy section of the Bosh life cycle which, as I understand it, could fit handily in this release as a post-deploy-script job, just like the pre-install-script job.

I have what I believe is working code (it seems to work in my OpsMan tile) that does this. I'll submit a PR shortly.

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/174502541

The labels on this github issue will be updated when the story is started.

[mrosecrance]

Done in https://github.com/cloudfoundry/os-conf-release/releases/tag/v22.1.1