Please read the following and notice that bulk update `find` doesn't even
match a document when `upsert => false`. Also notice with `upsert=>true` it does match a document but doesn't update the `products`. Doesn't make any sense. Is there a workaround?

2.1.7 :001 > class Something

2.1.7 :002?> include Mongoid::Document

2.1.7 :003?> field :products, :type => Array

2.1.7 :004?> end

=> #<Mongoid::Fields::Standard:0x007f83b4e075b0 @name="products", @options={:type=>Array, :klass=>Something}, @label=nil, @default_val=nil>

2.1.7 :006 > Something.delete_all

=> 0

2.1.7 :007 > Something.create :products => [1,2,3,4]

=> #<Something _id: 56ddec0464b1f31186000000, products: [1, 2, 3, 4]>

2.1.7 :008 > Something.first

=> #<Something _id: 56ddec0464b1f31186000000, products: [1, 2, 3, 4]>

2.1.7 :009 > Something.mongo_client[:something].bulk_write([{ :update_one => { :filter =>

{ "_id" => BSON::ObjectId("56ddec0464b1f31186000000")}

, :update => {"$set" => {"products"=>[6,7]}}, :upsert => false } }])

=> #<Mongo::BulkWrite::Result:0x007f83b1e4eb48 @results=

{"n_modified"=>0, "n_upserted"=>0, "n_matched"=>0, "n"=>0, "upserted_ids"=>[]}

>

2.1.7 :011 > Something.mongo_client[:something].bulk_write([{ :update_one => { :filter =>

{ "_id" => BSON::ObjectId("56ddec0464b1f31186000000")}

, :update => {"$set" => {"products"=>[6,7]}}, :upsert => true } }])

=> #<Mongo::BulkWrite::Result:0x007f83b1d5eff8 @results=

{"n_modified"=>0, "n_upserted"=>1, "n_matched"=>0, "n"=>1, "upserted_ids"=>[BSON::ObjectId('56ddec0464b1f31186000000')]}

>

2.1.7 :012 >