message: feat(writer): Increase UV_THREADPOOL_SIZE
  This increases the UV_THREADPOOL_SIZE to CPUs * 4 to
  facilitate full write speeds when writing to multiple destinations,
  in preparation for integrating multi-writes.
  Change-Type: patch
  Changelog-Entry: Increase UV_THREADPOOL_SIZE to allocate 4 threads per CPU
diff: @@ -31,6 +31,13 @@ const windowProgress = require('../os/window-progress')
  const analytics = require('../modules/analytics')
  const packageJSON = require('../../../../package.json')
  +/**
  + * @summary Number of threads per CPU to allocate to the UV_THREADPOOL
  + * @type {Number}
  + * @constant
  + */
  +const THREADS_PER_CPU = 4
  +
  /**
  * @summary Get application entry point
  * @function
  @@ -165,6 +172,7 @@ exports.performWrite = (image, drive, onProgress) => {
  IPC_CLIENT_ID,
  IPC_SOCKET_ROOT: ipc.config.socketRoot,
  ELECTRON_RUN_AS_NODE: 1,
  + UV_THREADPOOL_SIZE: os.cpus().length * THREADS_PER_CPU,
  // Casting to Number nicely converts booleans to 0 or 1.
  OPTION_VALIDATE: Number(settings.get('validateWriteOnSuccess')),
  