Test against Node.js v4.x.x

[madarche]

It is stated "4" and not "4.0" to test against minor updates of Node.js. Only the newest 4.x release is supported by upstream so it doesn't make sense to test specifically on 4.0. Node now follows semver so no breaking changes are allowed to land before Node 5.0.0.

[dougwilson]

Hi! It seems like this is a duplicate of the PR #2751 . If you are willing to move forward on this, please feel free to start working on the pre-requirements that are listed in #2751 (comment) :

It looks like there is more work to be done before I can merge your PR. I don't want to undermine the work you put into this and make the commit and discredit you, so I'll provide the remaining work for this PR so you can accomplish the tasks :)

1. Before we can add any new versions to our Travis CI, we need to ensure all of our sub dependencies are fully functional on those versions first. There are too many sub dependencies to list here, but you can find a list in the packagee.json file (https://github.com/strongloop/express/blob/master/package.json). Once every one is tested and updated to officially support Node.js 4.x, we can proceed.

2. We also need to examine the changelog of Node.js/io.js on majors to determine what is different, what the breaking changes are, and how do they relate to what this module does (unified changelog at https://github.com/nodejs/node/blob/master/CHANGELOG.md). This module deals with details of HTTP. Please verify this and let me know.

Let me know as your progress through this and if you get stuck or anything!

[madarche]

Cool. Thank you @dougwilson.