Refactor cnb buildpack pipeline template
Refactor cnb buildpack pipeline template

- Use hashes for buildpacks and their properties

Co-authored-by: Andrew Meyer <8f92422f5861fc9f31873f75dd770facd670512b@pivotal.io>

cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci