Cannot install on node 0.12

[hughes]

$ nvm use 0.12
$ npm install perfnow
...
npm ERR! fetch failed https://registry.npmjs.org/i/-/i-0.3.2.tgz
npm WARN retry will retry, error on last attempt: Error: fetch failed with status code 504

There's no mention of the i package in the shrinkwrapped dependencies, but it's somehow getting installed. Version 0.3.2 doesn't exist on npm.

In node 4.3, this dependency is not installed.

[daniellmb]

Yeah need take a look at the npm stuff it's all broken at the moment. Travis CI is failing as well. If you have time I'd welcome a PR to resolve it! :)