2019-04-29, Version 12.1.0 (Current)

Notable changes:

* intl:
  * Update ICU to 64.2. This adds support for Japanese Era (Reiwa).
    https://github.com/nodejs/node/pull/27361
  * Fixes a bug in ICU that affected Node.js 12.0.0 in the case where
    `new Date().toLocaleString()` was called with a non-default locale.
    https://github.com/nodejs/node/pull/27415
* C++ API:
  * Added an overload of `EmitAsyncDestroy` that can be used during
    garbage collection.
    https://github.com/nodejs/node/pull/27255

PR-URL: https://github.com/nodejs/node/pull/27440