Add node-pre-gyp to publish binaries

[caseywebdev]

This PR adds node-pre-gyp (https://github.com/mapbox/node-pre-gyp) to handle binary packaging and publishing. I tested npm install and npm run publish with my AWS creds for the atom-watcher-test S3 bucket I created and it all worked as expected.

A couple things will need to be handled by the maintainers of this package:

1. We'll need an S3 bucket for the binaries.
2. Upload creds for said bucket will need to be added to the CI tools.
3. A method of releasing builds will need to be decided. Common practices that I've seen:
   • Publish when a specific token exists in the commit message, ie [ci-publish]
   • Publish when a git tag is pushed

Alternate Designs

What node-pre-gyp does could be manually handled, but it seems node-pre-gyp is pretty well established and worked for me with minimal configuration.

Benefits

Uploading built binaries will save time for everyone wanting to install this package.

Possible Drawbacks

If a prebuilt binary doesn't exist, the tool will fallback and build locally, so there's little drawback to this addition.

Applicable Issues

Closes #134

/cc @smashwilson

[daviwil]

I prefer prebuild for this because it can auto-upload binaries to the tag's GitHub release, no S3 bucket needed. Any chance node-pre-gyp can do the same?

[caseywebdev]

Ah, didn’t know about preload. I agree it’s nicer to not add the S3 dep.

[caseywebdev]

Turns out there's a nifty node-pre-gyp-github plugin that uses GitHub releases as a publish target.

The only thing required for this new update to work is an envvar in the CI NODE_PRE_GYP_GITHUB_TOKEN=<token with release write access>

[Arcanemagus]

Looks like this may have snuck in from the previous S3 based solution?

[smashwilson]

Ah, possible. I can take it out and see if things still work?

[caseywebdev]

Yea that was a prereq for s3, should be removable.