use npx in package.json scripts

[msimerson]

Changes

• package.json: use npx in scripts (works everywhere- locally, GitHub Actions, Travis, AppVeyor)
• tls_socket: process all entries in config/tls dir. Uses async.map so previous versions would abort after the first error in a TLS cert was encountered. This surfaced in Windows test where initial err aborted processing of tls dir contents.
• ignore an SPF error (when DNS lookup fails) when testing on Windows

Checklist

• Changes updated
• tests updated

[baudehlo]

Is this even necessary? Node adds node_modules/.bin to the PATH anyway, so just eslint on its own should work fine.

[msimerson]

Generally, yes, if one values consistency. Do you want the tests run with the locally installed version of $dep in ./node_modules/.bin or the system installed one in /usr/local/bin or /usr/bin? Which is first in PATH? Is that the same on every platform?

[msimerson]

Generally, yes, if one values consistency.

I'm going to amend that slightly. I haven't tested this in a couple years. It used to be that the only way to get consistent passing CI tests on both Travis & Appveyor was to fully qualify the paths to the locally installed deps and precede that path with node. Nothing else consistently worked. Since then we have dropped a couple older versions of node.