As of 30 october 2018 this repository is being deprecated.
Please refer to the official npm publish.
Also, a blueprint for .npmrc and gemfury.io is provided:
always-auth=true
registry=https://<gemfury-registry>/<username>/
//<gemfury-registry>/<username>/:_authToken=<token>Publish private npm packages on gemfury.
npm i gemfury-publish$(npm bin)/gemfury-publish