我正在关注 Lynda ruby on rails 教程。我被要求输入“rake db:migrate”。然而，这是我收到的错误。
lexi87$ rake db:migrate
rake aborted!
/Users/lexi87/Sites/simple_cms/db/migrate/20130107145627_create_users.rb:14: syntax error, unexpected $end, expecting keyword_end
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:251:in `require'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:251:in `block in require'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:236:in `load_dependency'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:251:in `require'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:537:in `load_migration'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:533:in `migration'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:528:in `migrate'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:720:in `block (2 levels) in migrate'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:777:in `call'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:777:in `ddl_transaction'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:719:in `block in migrate'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:700:in `each'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:700:in `migrate'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:570:in `up'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/migration.rb:551:in `migrate'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/railties/databases.rake:179:in `block (2 levels) in <top (required)>'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/bin/ruby_noexec_wrapper:14:in `eval'
/Users/lexi87/.rvm/gems/ruby-1.9.2-p320/bin/ruby_noexec_wrapper:14:in `<main>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)
我在我应该在的目录中，即“sites/simple_cms”。我已经安装了 rake 并且还运行了“gem install bundle”和“bundle install”。我在目录中完成了此操作，然后在“站点目录”甚至主目录中完成了此操作。没有什么不同。