Papertrail

• First install PaperTrail

Note: you should use the --with-changes option when creating the version table
to ensure that history messages are recorded in a object_changes column.

$ bundle exec rails generate paper_trail:install --with-changes  
   Connecting to database specified by database.yml`
      create  db/migrate/20131113103143_create_versions.rb
      create  db/migrate/20131113103144_add_object_changes_column_to_versions.rb

• add the has_paper_trail statements to the tracked models
• add this to your rails_admin.rb initializer:

config.audit_with :paper_trail, 'User', 'PaperTrail::Version' # PaperTrail >= 3.0.0
config.audit_with :paper_trail, 'User', 'Version' # PaperTrail < 3.0.0

User should be your 'user' model.