ステージング サーバー (heroku 上) に変更をデプロイしようとしていますが、次のエラー メッセージが表示され続けます。
Matthews-MacBook-Air-2:iGiveMore WorkWell$ rake deploy staging --trace
rake aborted!
Don't know how to build task 'deploy'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/lib/rake/task_manager.rb:49:in `[]'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/lib/rake/application.rb:142:in `invoke_task'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/lib/rake/application.rb:101:in `block (2 levels) in top_level'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/lib/rake/application.rb:101:in `each'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/lib/rake/application.rb:101:in `block in top_level'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/lib/rake/application.rb:110:in `run_with_threads'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/lib/rake/application.rb:95:in `top_level'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/lib/rake/application.rb:73:in `block in run'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/lib/rake/application.rb:160:in `standard_exception_handling'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/lib/rake/application.rb:70:in `run'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/gems/rake-10.0.3/bin/rake:33:in `<top (required)>'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/bin/rake:23:in `load'
/Users/WorkWell/.rvm/gems/ruby-1.9.2-p290/bin/rake:23:in `<main>'
助けてください!