Compatibility with skaffold

[RoryShively]

PR #67

[RoryShively]

updated available commands in helm-secrets and have program exit with the exit code of the executed helm command to make this plugin compatable with skaffold

This PR will make helm secrets compatible with skaffold by allow the dep, get, and delete commands to be used with helm secrets. These commands are used by skaffold and although I've tried to see if their code could be modified to selectively use helm secrets on certain commands it was easier to go this route.

I also pass through the exit code of the helm command since thats used by skaffold as well.

[RoryShively]

Any update on getting this pushed through? I need this merged so I can start working with the skaffold community

[RoryShively]

@szibis Would like to get this pushed through. The skaffold community just excepted my proposal and I'm about to write a PR

[RoryShively]

I'm going to have to tell people to use my fork if this doesn't get merged and I don't want to maintain it if I don't have to