Doesn't install properly on node 8.4.0

[therebelrobot]

Hey, I couldn't find any documentation on this in the readme, but I may have missed it:

Does this library work in the latest LTS node (8.x.x)? I tried to get it installed but it bailed on the first go saying the node engine didn't match the required (6.x.x). I'd love to use this lib to automatically pen test new projects, but needing to downgrade to v6 would be non-starter for most of them, unfortunately.

Besides that, this looks like an amazing lib! Keep up the amazing work!