CYB-229 - Likes: hook the front-end up to the back-end

https://jira.ets.berkeley.edu/jira/browse/CYB-229
These 3 lines might work anyway, because of how "render :json" works, it will translate it to the right form.  Or do you want the bare values, not the strings 'true', 'false' and 'null'?   In which case this might render what you want.