Hi, When I run "rake assets:precompile RAILS_ENV=production" command, I have issue. rake assets:precompile RAILS_ENV=production rake aborted! Uglifier::Error: Unexpected token: punc ((). To use ES6...

Uglifier::Error: Unexpected token: punc ((). To use ES6 syntax, harmony mode must be enabled with Uglifier.new(:harmony => true) · Issue #127 · lautis/uglifier