ES2018 dependent code breaking on older versions of node

[HoraceShmorace]

RE: https://github.com/WP-API/node-wpapi/blob/master/wpapi.js#L218

Be careful of breaking changes between minor versions. The spreading of object properties wasn't supported until Node 8.2.1 (with the --harmony flag). Our project is on Node 7.2.1 (for reasons that would only elicit eye rolls), so the upgrade from wpapi 1.1.2 to 1.2x throws a runtime error. We had to switch the package.json semver entry from ^1.1.0 to strict 1.1.2.

For version 1.2.0, your changelog should reflect that the minimum supported Node version is now 8.2.1 (with the --harmony flag).

[kadamwhite]

@HoraceShmorace That is good feedback, and I appreciate your saying something. This was a result of my desire to get out an API-compatible version of the library on the 1.x branch featuring some useful bug fixes, but I hear and acknowledge that the two breaking changes in 1.2 should have been left for 2.0. We will do better next time.

The changelog does mention dropping support for Node <v8, but does not clarify the specifics of 8.2.1 vs 8.6. I will update the README and Changelog accordingly.

[kadamwhite]

README.d and CHANGELOG.md updated.

Less helpfully to your situation, the damage is done so I will not be reverting the change; 1.2 and later will continue to require a minimum of Node 8.6/8.2.1 --harmony. (We've all been there with non-upgradable systems, good luck sorting out whatever reasons keep you on v7 and apologies that subsequent 1.x branch bug fixes won't be available to you!)