Complete project refactor to typescript

[kaden-sharpin]

I know that this repo is long dead and this pull request will never be merged.
I made this fork for myself and thought I would try and share it.

Essentially, I completely:

• refactored the project to be promise-based
• use typescript, and
• updated the dependencies so npm stops freaking out about deprecated modules.

Big credit to @SimplyLinn for creating the type declarations that I worked off and implemented.

To install my fork in your projects: npm i git+https://github.com/kaden-sharpin/node-nat-upnp.git

[SimplyLinn]

As a tip, you could release this on npm as a scoped package by renaming it to "@kaden-sharpin/nat-upnp", making it easier to depend upon