fix(bake/chocolatey): Observe Chocolatey exit codes (spinnaker#276)

Currently, when installing multiple packages, all are installs are attempted and only the final exit code is used (it falls through to Packer scripts in $LastExitCode).  Instead, exit with the same exit code as soon as the first package install fails.

chore(packer): upgrade packer binary to 1.2.2 (spinnaker#271) (spinna…

…ker#272)

fix(install_packages): support for multiple repos (spinnaker#267)

fix(install_packages): support for multiple repos (spinnaker#268)

feat(bake/manifests): Add namespace support for Helm bakery (spinnake…

…r#261)

chore(Dockerfile): Fix packer url. (spinnaker#264)

fix(manifest): Fix using base64 artifacts in manifest bakery

chore(build): Gradle 4.7

chore(packer) - upgrade packer binary to 1.2.2 (spinnaker#244)

The addition of spot changed the defaults, swap them back (spinnaker#235

)

- Change the spotPrice default in the virtualizationSettings to 0
  instead of auto. Set to auto it was defaulting to doing bakes using
  spot, which is a big change from the way we have been operating.
- Need to quote the spot price in the templates, otherwise packer throws
  an error with "expected type 'string', got unconvertible type 'float64'"
- Leave the spotPriceAutoProduct set in the virtualization settings, so
  users can set just aws_spot_price in their bake stage and have it work
  as expected.