deps: upgrade to npm 2.14.3

Yay! New npm for node 4 :)

There's not much in this release that would affect node except a patch to our test suite to make the released version of npm pass its tests (which is what stopped the release 2 weeks ago from getting upstreamed).

Additionally, I've manually included an upgrade so we use node-gyp@3.0.3, which isn't officially part of this release but will be included in next week's (and is currently in npm@next).

See our release notes at https://github.com/npm/npm/releases/tag/v2.14.3

r: @Fishrock123 r: @chrisdickinson