Prepack

[brettz9]

• npm: Add prepack script to run test-lite (per https://github.com/d3x0r/JSON6/issues/34#issuecomment-634228709 )
• Linting: Prefer const (these linting errors weren't caught because the PR that added them was merged before the linting-pkg-json merge and only changes are linted; going forward, future linting errors should be caught)

Btw, if you are only looking to see the files that are changed, it may be simpler to just run npm publish --dry-run. If you don't actually need pack, we could change the script where it runs to prepublishOnly.

[brettz9]

Btw, I see the Travis builds are failing since we are using the current ESLint 7 version which has a minimum of Node 10. Travis could be set up to downgrade to earlier ESLint versions, but it adds some complexity.

Btw, you may want to add the free open source integration for Travis so we can see the Travis status within PRs. I believe you can use this link to set it up: https://github.com/marketplace/travis-ci (as mentioned below on the page, it is free for open source)

[d3x0r]

well I use pack so I can check the .tgz and make sure I didn't accidentally include any other stray files; 'sides that lets me keep a copy around for quick local install from tarball ...

Ya Travis integration can be added; I forgot how I set that up for another project; but I'll look into that shortly.