add compile-bosh-releases-command

[crhntr]

This change adds a kiln compile-bosh-release-tarballs command.

$ kiln compile-bosh-release-tarballs --help
kiln compile-bosh-release-tarballs
upload bosh release tarballs to a bosh director, compile the packages against the stemcell from the stemcell lock, and download the compiled tarballs

Usage: kiln [options] compile-bosh-release-tarballs [<args>]
  --help, -h     bool  prints this usage information (default: false)
  --version, -v  bool  prints the kiln release version (default: false)

Command Arguments:
  --kilnfile            string  path to Kilnfile (default: Kilnfile)
  --releases-directory  string  path to a directory containing release tarballs (default: releases)
  BOSH_ALL_PROXY        string
  BOSH_CA_CERT          string
  BOSH_CLIENT           string
  BOSH_CLIENT_SECRET    string
  BOSH_ENVIRONMENT      string
  BOSH_ENV_NAME         string

Note the only way to set the BOSH variables is via the environment. These variables match the ones set by smith and BBL.

TODO

• design the command name and flags
• write an implementation that takes local tarball files and writes them locally
• add flag to specify which release source to upload to. The flag should be the similar flag in cache-compiled-releases and should be named --upload-target-id
• update the Kilnfile.lock after the download/export succeeds

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this. Unfortunately, the Pivotal Tracker project is private so you may be unable to view the contents of the story.

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

[crhntr]

This is not longer how we want to do this. We may wrap an image with cloudfoundry/bosh-agent#315 in the future but for now this PR should be closed.