无法加载从GitHub获取的Rails应用程序; 耙,rails服务器不工作

我从GitHub存储库中克隆了一个app文件夹,在bundle安装gems后,我尝试使用rake db:reset和rake db:migrate命令,两者都没有工作,这是我的错误信息:

>[app_folder]rake db:reset
rake aborted!
Could not load database configuration. No such file - /Users/harry/Dropbox/apps/app_folder/config/database.yml
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/application/configuration.rb:110:in `database_configuration'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/railtie.rb:174:in `block (2 levels) in '
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:27:in `each'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:27:in `on_load'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/railtie.rb:173:in `block in '
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `instance_exec'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `run'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/initializable.rb:55:in `block in run_initializers'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/initializable.rb:54:in `run_initializers'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/application.rb:215:in `initialize!'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
/Users/harry/Dropbox/apps/app_folder/config/environment.rb:5:in `'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `block in require'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/application.rb:189:in `require_environment!'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/application.rb:249:in `block in run_tasks_blocks'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/bin/ruby_executable_hooks:15:in `eval'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/bin/ruby_executable_hooks:15:in `
'
Tasks: TOP => db:reset => environment
(See full trace by running task with --trace)
[app_folder]

当我尝试运行rails server或rails console时,我遇到了类似的错误.非常感谢任何帮助!! 非常感谢!