deps: upgrade to npm 3.3.6
This is the big npm@3 integration. 3.3.6 is the version that fixes the major speed regression.
This will require https://github.com/nodejs/node/pull/3308 to land first for tests to pass.
As you are all aware, all kinds of stuff has changed. The changelog for this release in particular is here:
https://github.com/npm/npm/releases/tag/v3.3.6
And the original changelog for 3.0.0 is here:
https://github.com/npm/npm/releases/tag/v3.0.0
r: @Fishrock123 r: @chrisdickinson