Add :touch option to model save method

Ruby on Rails active_record has option {touch: false}, when record is saved to database, since version 5. https://blog.bigbinary.com/2016/05/09/rails-5-allows-updating-without-updating-timestamps.html

I can not find if this (or similar) option is implemented in mongoid too. I can see that mongoid has options parameters implemented on save method, but it looks like they are ignored.

Can you please implement this functionality.

by
TheR