Rails 4 - Strong Parameters(Mass Assignment Security Error)

Hi,
 While trying to execute "bundle exec etl etl/process_all.ebf" ,
I'm getting the following error

"/home/victor/.rvm/gems/ruby-2.1.0/gems/activemodel-4.0.2/lib/active_model/deprecated_mass_assignment_security.rb:14:in attr_accessible':attr_accessibleis extracted out of Rails into a gem. Please use new recommended protection model for params(strong_parameters) or addprotected_attributes` to your Gemfile to use old one. (RuntimeError)"


Please help me resolve this issue