Allow for automatic generation of templates from helm

[pratikmallya]

helm is a popular k8 manifest manager and is often used by many OSS tools.

The workflow I've been used to recently for dealing with helm has been:

• generate valid manifests using helm generate ...
• separate out the manifests "by hand" into different files etc.

It would be nice if there was a utility which just did that for me.

e.g.

helm template | bundle exec kdt template -

would spit out a bunch of erb templates, one per each k8s resource.

Probably want to exclude secrets.

This would also allow for e.g. easy updates, as a user could run the same command, then examine a git diff to see the difference from existing templates. Although if the manifests have been customized a lot there would likely be a lot of noise in the diffs.