Discovered in #841, [this comment](https://github.com/shelljs/shelljs/pull/841#issuecomment-387068159). Basically, fix [this line](https://github.com/shelljs/shelljs/blob/master/appveyor.yml#L15). We shouldn't install the latest npm all the time, because it may not be supported on older node versions. High priority, because this will fail the next master build.
Discovered in #841, this comment.
Basically, fix this line. We shouldn't install the latest npm all the time, because it may not be supported on older node versions.
High priority, because this will fail the next master build.