Add coffee-rails dependency removal to changelog
Add coffee-rails dependency removal to changelog

This is technically a breaking change because ActiveAdmin introduced
this dependency in to applications in the past by generating a `.coffee`
file on people's apps, and now it is removing it. Thus, applications
will fail to boot because of this reason, and need changes to migrate.

activeadmin/activeadmin,vraravam/activeadmin,javierjulio/activeadmin,deivid-rodriguez/activeadmin,javierjulio/activeadmin,vraravam/activeadmin,vraravam/activeadmin,mrjman/activeadmin,mrjman/activeadmin,deivid-rodriguez/activeadmin,javierjulio/activeadmin,activeadmin/activeadmin,mrjman/activeadmin,deivid-rodriguez/activeadmin,activeadmin/activeadmin