update Node.js versions used in Travis CI checks

[striezel]

Node.js versions below 10.x are not maintained anymore, so it is probably best to use some newer, still maintained versions.
For release cyles of Node.js see the official site: https://nodejs.org/en/about/releases/.

[striezel]

It seems that AppVeyor cannot install Node.js 16 yet: https://ci.appveyor.com/project/browserify/browserify/builds/39074493/job/f56gjo1d8f1odghj
Therefore I had to remove Node.js 16 from AppVeyor's build matrix.

[striezel]

@ljharb: Checks with old versions of Node.js fail on Travis and AppVeyor, but that happened on the current commit of the master branch (0ec6e80), too. So I guess that is how it is supposed to be.

[striezel]

Since there has been no activity here for almost a week: Is there anything else blocking this PR? Any more change requests? If so, please let me know.
Thanks. :)

[ljharb]

LGTM

[striezel]

@ljharb:

LGTM

Good.

Since this pull request has been approved one and a half month ago but it has not been merged yet: Is there anything else to do? If not, can someone merge it please?
Thanks. :)

[ljharb]

@striezel tests are failing on master in node < 4, and altho i reviewed this PR, i don't typically maintain browserify, so it needs to wait for the maintainers.

[striezel]

@goto-bus-stop or who is currently maintaining browserify: Is there a chance to get a review on the changes?

Is this still relevant after almost a year now?

[legobeat]

@ljharb @goto-bus-stop @feross Would dropping 0.10 and 0.12 be up for reconsideration alongside #2070 ?

Split that out to #2071, which does not overlap with this PR.

[ljharb]

Nope, we will continue to support them.

[striezel]

@striezel tests are failing on master in node < 4, and altho i reviewed this PR, i don't typically maintain browserify, so it needs to wait for the maintainers.

So who is typically maintaining browserify? Should I ping anybody?

As for Node < 4, that versions already failed before that pull request:

Seeing that the Travis CI jobs of the current commit on the master failed for Node.js 4 and older I just assumed they were not supported by browserify anymore.

I'll re-add those old versions then. Not fixing any tests that fail on those old versions, though.

However, there have been no browserify builds on Travis CI for quite a while, and I suppose it might be time to consider a switch, e. g. to GitHub Actions. So part of this PR may not be relevant anymore, and there possibly should also be CI runs for Node.js 18 and 20, too.