Generate Certs for Mutation/Validatiion Webhooks

[markmandel]

Now that we have #101 (Helm) we can use it to generate the cert for the validation and mutation webhook at installation time.

Design

Looks like it should be relatively straight forward, as there is a genSignedCert function built into helm. See examples below.

We will need to change the controller so that it pulls the cert that it uses from a generated Secret.

This should be relatively straightforward as it already reads the certs a file , we'll just need to not add them in the Dockerfile and make sure to mount the Secret in the controller deployment

Research

https://github.com/lachie83/internallb-webhook-admission-controller/blob/master/charts/internallb-webhook-admission-controller/templates/admissionregistration.yaml
https://github.com/kubernetes/helm/blob/master/docs/charts_tips_and_tricks.md
http://masterminds.github.io/sprig/crypto.html