crypto: update root certificates
I picked the certdata.txt from upstream NSS instead of downstream Firefox this time around in order to include the January CA updates.
If we end up delaying the node 8 release for a few weeks, we should consider upgrading to NSS 3.31 to include the March updates as well.
cc @nodejs/crypto, refs #12393 (closed).
CI: https://ci.nodejs.org/job/node-test-pull-request/7380/ CITGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/715/