See https://github.com/helm/helm-classic/pull/306 for helm classic
and
https://kubernetes.slack.com/archives/C51E88VDG/p1520588964000061

* Add "--namespace" to helm lint

Keep lint syntax as close as possible to "helm install" resp. "helm
upgrade", so that one only needs to change the command.

See #2036

* Align lintCmd struct

* Add "--set" and "--values" to helm lint

Keep lint syntax as close as possible to "helm install" resp. "helm
upgrade", so that one only needs to change the command.

Closes #2495,#2036

* Reuse strict parameter, when rendering during lint

We want to see the rendering fail, if we missed a value, so we reuse
"--strict".

See #2495,#2036

* Fix lint unit test

See #2495,#2036

* Update docs

Each maintainer can have an optional URL. There are seceral use
cases for providing a URL instead of an email address:
- The case where a maintainer wants to hide their email address
  behind a webform for personal security
- When the maintainer is an organization and feedback should
  go to an issue queue

This change:
- Adds the proto field for url
- Updates the generated files for the chart proto
- Includes linting for the url
- Updates the docs to include the url

Closes #3056

Closes #2393

since kubernetes 1.4, the upper limit for resource name is 63 characters,
so it is better to change the template when running `helm create` accordingly.

This adds the {{.Capabilities}} object to the template variables so that
chart authors can write charts that are aware of teh Kubernetes
capabilities of the current cluster.

Closes #1608

resolves #1463

Long ago, Helm did not support cross-namespace installs. There was a
linter rule to catch this. When we changed the way Helm worked, we did
not remove the linter rule. This commit removes that linter rule.

Closes #1489

This adds a function engine.FuncMap that returns a function mapping that
better represents the functions passed to a template. The linting logic
is reconfigured to use this function instead of the sprig.FuncMap
function.

Closes #1366

The YAML validation was broken because the renderedContentMap has keys
with the path to the template including the chart directory, whereas the
linter was trying to access it relative from the chart directory.

For example, the hash key was `drupal/templates/deployment.yaml` but the
linter was trying to access `templates/deployment.yaml`. This commit
fixes the key used to access the rendered content.

Fixes the regex for extracting templates to include templates that
suppress newlines and ignore any conditional flow statements.

This removes the last of the requests for gopkg.in/yaml.v2, and
also the struct annotations.

Closes #1192
Closes #1263

closes #1161

https://golang.org/doc/go1.4#canonicalimports

Handle a previously unhandled error in the linter. This simply bails out
if a chart's values files do not parse.

Also, changed the implementation of CoalesceValues to return a map even
on error.

* part of #836

Closes #847.

Fixing unit test