updateMany (records, opts) {
    return this.crud('updateMany', records, opts)
  }
Given an array of updates, perform each of the updates via an adapter. Each
"update" is a hash of properties with which to update an record. Each
update must contain the primary key of the record to be updated.

{@link Mapper#beforeUpdateMany} will be called before making the update.
{@link Mapper#afterUpdateMany} will be called after making the update.

@example
PostMapper.updateMany([
  { id: 1234, status: 'draft' },
  { id: 2468, status: 'published', published_at: new Date() }
]).then((posts) => {
  console.log(posts); // [...]
});

@fires Mapper#beforeUpdateMany
@fires Mapper#afterUpdateMany
@method Mapper#updateMany
@param {Record[]} records Array up record updates.
@param {object} [opts] Configuration options. Refer to the `updateMany`
method of whatever adapter you're using for more configuration options.
@param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
adapter to use.
@param {boolean} [opts.notify={@link Mapper#notify}] See {@link Mapper#notify}.
@param {boolean} [opts.noValidate={@link Mapper#noValidate}] See {@link Mapper#noValidate}.
@param {boolean} [opts.raw={@link Mapper#raw}] See {@link Mapper#raw}.
@returns {Promise} Resolves with the updated records. Rejects if any of the
records could be found.
@since 3.0.0
@tutorial ["http://www.js-data.io/v3.0/docs/saving-data","Saving data"]