try to remove some deprecated/unmaintained deps

[aladdin-add]

To some extend, deprecated deps mean unhealthy. While I'm not seeing depth=1 deprecated deps in eslint, but

• a) some seems unmaintained, e.g. levn;
• b) some depth>1 deps seems deprecated. (filing an issue in these repos might be a good idea)
  
  https://travis-ci.org/eslint/eslint/jobs/408555040#L430

I think it make sense to upgrade/remove these deps. a few thoughts on this(and want to get help from the community ✋ ):

• find out deprecated/unmaintained deps.
• if still maintained, upgrade to latest.
• if not maintained, find a high-quality alternate.
• if can't find a qualified alternate, write own.
• or keep it. ◑﹏◐

refs:

• https://www.nczonline.net/blog/2015/12/why-im-not-using-your-open-source-project/
• http://npm-introspect.z3d.tech/?packages=eslint

[mysticatea]

About levn, I don't think we should change it because it's a part of our public API (it parses CLI arguments and /*eslint ...*/ directives).

About deprecated indirect dependencies, those seem to come from beefy, karma, and sinon.

> npm ls leftpad formatio nodemailer wrench uws mailcomposer socks node-uuid buildmail
eslint@5.2.0 C:\Users\starc\Documents\GitHub\eslint
+-- beefy@2.1.8
| `-- leftpad@0.0.0
+-- karma@2.0.5
| +-- log4js@2.11.0
| | +-- loggly@1.1.1
| | | `-- request@2.75.0
| | |   `-- node-uuid@1.4.8
| | +-- mailgun-js@0.18.1
| | | `-- proxy-agent@3.0.1
| | |   +-- pac-proxy-agent@2.0.2
| | |   | `-- socks-proxy-agent@3.0.1
| | |   |   `-- socks@1.1.10
| | |   `-- socks-proxy-agent@4.0.1
| | |     `-- socks@2.2.1
| | `-- nodemailer@2.7.2
| |   +-- mailcomposer@4.0.1
| |   | `-- buildmail@4.0.1
| |   `-- socks@1.1.9
| `-- socket.io@2.0.4
|   `-- engine.io@3.1.5
|     `-- uws@9.14.0
`-- sinon@3.3.0
  +-- build@0.1.4
  | `-- wrench@1.3.9
  `-- formatio@1.2.0

• I'm not sure what does beefy do. Can we remove it?
• We are using the latest karma, but most deprecated dependencies come from karma. Probably we have to find an alternative for karma and phantomjs. Maybe puppeteer and ...? As a side note, we should consider drop the support of IE11 for our online demo since we cannot test for ES5 environment if we switch phantomjs.
• We are using very old sinon. Upgrading may solve it.

[aladdin-add]

@mysticatea thanks for you feedback!

👍 to switch to puppeteer, and upgrade sinon.

As for levn, I should have given more background. There is a known issue (#9366). We might need to make a decision to:

• fork the repo, and fix the bug (though it was written in livescript).
• or implement our own, and passed its tests.
• or another way?

[mysticatea]

Should we open an issue on the levn repo at first? Because that repo has no issue in a long time, it means they have not needed to change their code.

[eslint-deprecated]

Unfortunately, it looks like there wasn't enough interest from the team
or community to implement this change. While we wish we'd be able to
accommodate everyone's requests, we do need to prioritize. We've found
that issues failing to reach accepted status after 21 days tend to
never be accepted, and as such, we close those issues.
This doesn't mean the idea isn't interesting or useful, just that it's
not something the team can commit to.

Thanks for contributing to ESLint and we appreciate your understanding.