remove engine:'^4' in package.json

[janryWang]

error [email protected]: The engine "node" is incompatible with this module. Expected version "^4".

my node version is v5.5.0

[jackycute]

are you using node version below 4?
I think this issue comes from yarn, am I right?

[JorgenEvens]

This is preventing us from using yarn on one of our projects. We are using node v6.

[domchristie]

If anyone fancies creating a pull request for this that'd be great.

[jackycute]

I've mentioned this issue in yarn, but it seems to be solved few days ago.
yarnpkg/yarn#623
And fixed issue is yarnpkg/yarn#647

So maybe upgrade yarn and install again will solve this issue.

[JorgenEvens]

I was using the latest version of yarn, seems like they only fixed the --ignore-engines flag.
Created a PR to resolve this issue with the correct version specification.

[jackycute]

You're right, I mean this engine number specified with "^" is not compatible with yarn.
It should be ">=" like your PR.
Good Job @JorgenEvens !