CI: Auto-Deploy Strategy

When a change is merged to the master branch of this repo, it would be ideal if we had the confidence in CI to auto-deploy Jenkins itself. The auto-deploy process might look something like:

1. `helm repo update` to fetch latest version of `jenkins` chart existing at `https://charts.deis.com/jenkins`
2. Once auth'd with k8s cluster that Jenkins is running on,
```
helm get values jenkins > current-values.yaml
helm upgrade jenkins deis-jenkins/jenkins \
-f current-values.yaml \
--set Master.ImageTag=git-$(git rev-parse --short HEAD)
```

Might also consider only doing this when/if an official release tag is pushed...

The auto-deploy would also need to be zero-downtime; or at least somehow scheduled for when Jenkins isn't running any jobs.

Start by reviewing the repository's CI configuration and the Helm commands described in the issue, including authentication to the Kubernetes cluster and retrieval of current values. Done means a defined merge or release trigger can deploy Jenkins with the current values, preserves availability, and avoids interrupting running jobs.

Written by the indexing model from the issue text.