Publishes a package to the registry so that it can be installed by name. Possible values in the 'packages' array are:
<folder>: A folder containing a package.json file
<tarball>: A url or file path to a gzipped tar archive containing a single folder with a package.json file inside.
If the package array is empty, npm will try to publish something in the current working directory.
This command could fails if one of the packages specified already exists in the registry. Overwrites when the "force" environment variable is set.