Run npm command v1.0.0


#1

The npm step has been extended with an input where you can provide a preferred npm version to use. The supplied version will be installed before running your npm command.

Previously, we used the system preinstalled version. With this new release, we first check user provided version, then check the package.json and only after then we fall back to the system installed version. If no npm is found, we install the latest available version from the operating systems package manager.

The step has been migrated onto the Go toolkit from plain shell.