Update CI configs

[kfarnung]

• Fix missing pip in macOS builds
• Add new builds to the matrix

[kfarnung]

https://travis-ci.org/kfarnung/node-addon-api

The matrix is pretty large now, I'm open to suggestions for reductions.

[mhdawson]

We actually run the tests across platforms here: https://ci.nodejs.org/view/x%20-%20Abi%20stable%20module%20API/job/node-test-node-addon-api/

Right now we run master nightly, and the others when we create releases. We should at least document that there are 2 places to look, if not try to cover them both in the community CI.

[kfarnung]

I wasn't aware of that, I just had Travis-CI setup for my fork and it was failing for a while. Does the that CI run include older versions of node as well?

[kfarnung]

I think it's either worth landing these changes or deleting the files. Do we have any node-addon-api CI coverage for ChakraCore in the official CI?

[mhdawson]

If you mean in the official CI for the n-api tests, no. I assume it would be a clone of the existing job, with possibly a smaller set of supported platforms, and then have it pull the chakra published versions. It does depend on binaries being already built/available.

[kfarnung]

We do have official builds: https://nodejs.org/download/chakracore-release/
And nightly builds: https://nodejs.org/download/chakracore-nightly/

For platforms we currently support Windows (x86 and x64), macOS (x64), and Linux (x64).

[mhdawson]

LGTM, will land and we can continue to discuss how to improve testing.

[mhdawson]

Landed as 12b2cde