Support deploying remote helm charts

[nkubala]

Fixes #1615

this adds a boolean remote field to the releases stanza of helm deploys in the skaffold config. it's used when computing the dependencies for a helm release: if a chart path is specified as remote, skaffold will skip it when listing the dependencies for the deploy.

deploy:
  helm:
    releases:
      - name: redis
        chartPath: stable/redis
        remote: true
        skipBuildDependencies: true // not necessary when `remote:true` is specified

since dependency building doesn't make sense for remote helm charts (e.g. helm dep build stable/redis doesn't work), we skip this by default when remote: true is specified by the user.

remote: true ==> skipBuildDependencies: true

[priyawadhwa]

just a nit

[tejal29]

Can we add some tests which return no dependencies for remote charts?

[balopat]

LGTM

the tests are added

[dahovey]

This is a feature I need for development, but I'm not familiar with building a go project and I need a Windows binary. Are there edge builds available somewhere?

[dahovey]

I see this was just released today. Thank you!!