charts ci: ability to inject any/all component chart versions

[vdice]

We currently have the ability to inject any/all component commit SHAs for accessing and using the correlating Docker image artifacts, e.g., CONTROLLER_SHA=abc1234 would eventually get injected into the Workflow chart as controller.docker_tag=git-abc1234

We need a similar ability to inject any/all component chart versions for overriding the defaults in Workflow's requirements.yaml, e.g., CONTROLLER_CHART_VERSION=v2.12.1-20170329233450-sha.bbc97a2 would eventually get injected into the Workflow chart's requirements.yaml before publishing.

Current thought is the REPO_TYPE=[pr | dev] set for the Workflow publishing job would trickle down for all <COMPONENT>_CHART_VERSION env vars as well. So, if REPO_TYPE=pr, a specified CONTROLLER_CHART_VERSION would be paired with the controller-pr chart repo for attempting helm dependency build, etc.

[Cryptophobia]

This issue was moved to teamhephy/jenkins-jobs#5