align our required version to the current LTS+

[rgbkrk]

Also changed our tagline / description for the package.json. I'd like to get 4.7.0 out.

Went ahead and upgraded the version of prebuild-install while I was at it. I think that's most of the maintenance level tasks that are needed here.

Closes #263

[n-riesco]

This needs to be released with a change in the major version number.

[rgbkrk]

Works for me, we're likely going to deprecate some methods we can't support with an upcoming N-API implementation from #189.

We should put deprecation warnings in for each of the methods, can you make a PR with the ones we should stop supporting @rolftimmermans?

[lgeiger]

I think technically we can make this node": ">=5.0 since prebuild only dropped support for Node 4.

[rgbkrk]

That's great that prebuild can support further back! Since the N-API changes coming up are going to force us into requiring 8.x+, I'd like us to push a bit further forward (old releases of ours will still work for those wanting to stick around on old node.js version). Aligning with 6.x puts us in sync with the node LTS schedule

[n-riesco]

Does prebuild-install@5 add any functionality we need?

[rgbkrk]

These are the main changes to prebuild-install:

• Several dependencies had vulnerabilities -- Update nsp and rc to fix vulnerabilities prebuild/prebuild-install#82
• Handle when older prebuilds are not found -- https://github.com/prebuild/prebuild-install/pull/84/files

Beyond that, I like to move ahead to match with our primary dependencies because we should opt in to fixes from them in their 5.x series. I can't imagine they'll be supporting a 4.x series solely for us to handle security upgrades (and is in fact part of what they moved forward with in 5.0.0).

[lgeiger]

Thanks for keeping us moving 👍